The Harlequin Shark (Labeo cyclorhynchus) is native to the middle and lower Congo river basin in the Republic of the Congo, the Democratic Republic of the Congo, and the Ogooué drainage in Gabon, Africa.    It is also known to tropical fish keeping enthusiasts as the Harlequin Sharkminnow, or Varigated Shark.

The Harlequin Shark inhabits densely vegetated clear water rain forest streams with thick marginal vegetation.    They are usually collected over silt littered substrates in tannin stained waters that are littered with leaves, downed tree branches, and other decomposing organic matter where like other Labeo species, they are primarily aufwuchs feeders that  graze along the bottom for microscopic animals, algae, and other detritus.

In their natural habitat, Harlequin Sharks are aggressive loners that lead a solitary lifestyle and except during the spawning season, avoid coming into contact with others of their own kind.  They are a highly territorial fish that under no circumstances should be kept with other Labeo or Epalzeorhynchos species, including their own kind.    You can expect that most bottom dwelling species such as Bichirs or catfish to be constantly bullied by the Harlequin Shark.

Harlequin Shark (Labeo cyclorhynchus)

The Harlequin Shark has an unusual gray black mottled body coloration over a creamy yellow base.   Their fins are translucent with black mottling and their bodies are shaped like Black Sharks or Rainbow Sharks.

Juvenile Harlequin Sharks have magnificent colors and markings, but their colors fade somewhat as they age.  They are notoriously hard to sex, but females are much more thicker bodied than than males, especially when in spawning condition.

Harlequin Sharks are best kept alone or in an African biotope setting with other robust, fast swimming, mid or top water species such as the larger Barbs, Danios, African Characins like  Arnoldichthys spilopterus, Brycinus longipinnis, Phenacogrammus or with some of the non African cyprinids.  They cannot be kept with others of their own kind, nor with other species that share their same body shape.   As juveniles, the Harlequin Shark will spend the majority of their time hiding but as they grow, they become highly territorial and extremely aggressive.

Harlequin Sharks require a well maintained, aged, densely planted, 55 gallon or larger aquarium set up with a silty and round rocky gravel substrate, variably sized rocks and small boulders, some driftwood branches, and plenty of nooks and crannies that can be used for hiding places.   Hardy plants such as Bolbitis, Java Fern, or Anubias can be grown and attached to the rocks or driftwood to promote the growth of algae and biofilm that the fish graze on.  Because they are a river dwelling species, the use of a powerhead in the tank is recommended to provide the beneficial current they need.

Because the Harlequin Shark is so intolerant of their own kind and almost impossible to accurately sex, there have been no successful breeding of this egg laying species in an aquarium environment.

In the wild, Harlequin Shark are highly adaptable feeders.  Some groups have become specialized towards a particular method of feeding and have been  recorded living among groups of hippopotamus, browsing on their bodies.    In an aquarium environment, they should be offered regular meals of small live, frozen or freeze dried foods such as mosquito larvae, bloodworms, Daphnia, and brine shrimp along with a good quality flake food, sinking granules, algae wafers, and plenty of vegetable matter.   Blanched spinach, shelled peas, cucumber, and finely chopped fruits make good additions to their diet and will promote their colors.

Unfortunately, Harlequin Sharks are not a common item in most tropical fish keeping shops however, from time to time they are available online from importers and specialty shops as juveniles and occasionally adults.

Harlequin Shark (Labeo cyclorhynchus)

Minimum Tank Size: 55 gallons
Care Level: Moderate
Temperament: Highly Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-81°F, dH 3-15°H, pH 6.0-7.5
Max Size: 6″
Color Form: Black, Gray
Diet: Omnivore
Compatibility: Single species tank
Origin: Central Africa
Family: Cyprinidae
Life Span: 4-6 years
Aquarist Experience Level: Intermediate

The Sand’s Cory (Corydoras davidsandsi) is endemic to the lower rio Negro in Brazil where it primarily inhabits tannin stained flooded forests, creeks, and “whitewater areas” with little detectable water hardness, an acidic pH, and very low conductivity.

The Sand’s Cory is a facultative air breather that possess a modified intestine that has evolved to facilitate the breathing of atmospheric oxygen.   This allow the fish to survive in oxygen depleted environments where other species would perish and is why they will occasionally rise to the surface in your aquarium to gulp in air.

Like other Corydoras they have stiffened pectoral fin spines that are capable of piercing the skin and causing a painful sting.  Secretions from the axillary glands at the base of the spines are venomous and mildly toxic, so care should be exercised when handling them.

Sand’s Cory (Corydoras davidsandsi)

The Sand’s Cory is similar to Corydoras melini in looks.   Both fish are tan and have a black stripe that runs from the lower dorsal fin to the lower caudal fin, just past the caudal peduncle.   However, when viewed from above, the black line splits above the caudal peduncle in the Sand’s Cory and in most other Cory species, it does not.

Additionally, it can be distinguished from Corydoras melini by it’s having a pale orange area between the dark facial stripe and the dorsal bars, and by lacking additional dark markings on it’s flanks.  Aside from the vertical eye stripe and the aforementioned back stripe, the flanks of C. davidsandsi are without further pigmentation.

Female Sand’s Corys are longer and plumper when viewed from above, especially during spawning.

The Sand’s Cory is a peaceful, gregarious species that should be housed with at least 4 to 6 of their own kind.  They are best kept in at a densely planted aquarium of at least 20 gallons or larger, with a sand or fine gravel substrate, some driftwood and rocks to provide cover, and a good filtration system that provides a small amount of current.   These fish require clean water and low nitrites to remain disease free.

The Sand’s Cory has been bred in an aquarium environment.   Two males per female should be placed in a breeding tank furnished with a sandy substrate, some plants and driftwood. When the female is visibly full of eggs, perform a 50 to 70% water change and place a small power filter or powerhead into the tank to increase oxygenation and water flow.   Repeat the water changes daily until the fish spawn.

The eggs are normally laid on the driftwood, among the plants, on spawning mops, and occasionally on the sides of the tank glass.  After spawning, either the parents or the eggs should be removed from the spawning tank.

If the eggs are removed, place them in the same well oxygenated water as the spawning tank and add a few drops of Methylene Blue or some Indian Almond Leaves to prevent fungus from developing.

In 3 to 4 days the eggs will hatch and the fry will be free swimming in another 3 days or so.   Feed the fry microworms or newly hatched brine shrimp until they are able to eat crushed flake food.

In their natural habitat, Sand’s Corys are omnivores that forage along the bottom for small insects, worms, crustaceans, and plant matter.   In an aquarium environment, they will accept most sinking dried foods, as well as live, frozen, and freeze dried bloodworms, Tubifex, blackworms, brine shrimp, etc.

They should not be expected “clean” the bottom and survive on any foods “left over” from other inhabitants of the aquarium. A well balanced diet is essential to their well being.

The Sand’s Cory is a relatively new addition to the tropical fish keeping hobby and is occasionally available online or from specialty fish shops. They are often imported with mixed shipments, and when available for purchase are usually 3/4″ to 1-1/4″ long.

Sand’s Cory (Corydoras davidsandsi)

Minimum Tank Size: 20 gallons
Temperament: Peaceful
Aquarium Hardiness: Hardy
Water Conditions: 68-77° F, KH 2-12, pH 6.2-7.2
Max. Size: 2½”
Color Form: Black, White
Diet: Omnivore
Compatibility: Great in community tanks
Origin: Brazil
Family: Callichthyidae
Lifespan: 6 Years or more
Aquarist Experience Level: Beginner to Intermediate

The common Goldfish (Carassius auratus) is a relatively small member of the carp (cyprinid) family that is one of the most commonly kept aquarium species in the world and arguably one of the earliest fish to be domesticated.

Special Pearlscale Goldfish (Carassius auratus)

Goldfish are a domesticated version of the less colorful carp species (Carassius auratus) native to east Asia.  They were first domesticated over a thousand years ago by the Chinese where several distinct breeds have since been developed.    Though they may resemble ornamental carp, Goldfish lack the barbels in the mouth area, the markings at the base of the scales, and do not grow as large as carp and Koi.

For thousands of years in ancient China, various species of (Asian) carp were domesticated and reared as food fish.

During the Jin dynasty (265–420), breeders observed that some of these normally gray or silver Asian carp produced red, orange, or yellow color mutations.    Later, during the Tang dynasty (618–907) when it became popular to raise carp in ornamental ponds and water gardens, a yellowish orange (gold) genetic mutation was produced from the normal silver colored variety and people began to selectively breed them instead of the silver variety.

Goldfish domestication was firmly established by the Song dynasty (960–1279) and because yellow (gold) was the imperial color, the empress ordered the collection of all the red and gold varieties of goldfish and made it unlawful for the common people to keep goldfish of the yellow variety.   This is no doubt this is why there are more orange than yellow goldfish, even though yellow goldfish are genetically easier to breed.

During the Ming dynasty (1368–1644) Goldfish began to be raised indoors.  This allowed breeders to selectively breed mutations (such as the fancy tailed goldfish) that would not have been able to survive in outdoor ponds.

During the 1600s, Goldfish were introduced into Japan, Portugal, and other parts of Europe where they were highly regarded as a symbol of good luck and fortune.   They were not introduced into North America until around 1850 where they quickly became popular with tropical fish keeping enthusiasts.

There are currently about 300 recognized breeds of “goldfish” in China.  Selective breeding over the centuries has produced many color variations, body shapes, fin types, and eye configurations that may be hardier or less hardy than the “wild” Prussian carp (Carassius auratus gibelio) they were originally bred from.

Today, the majority of goldfish breeds originated from China and since it is virtually impossible to list them all, we have chosen some of the main and more popular varieties and listed them below:

The Common goldfish differ only in color from their closest relative, the Prussian or Gibel carp.   They are found in a variety of colors including red, orange, gold, white, black and yellow, and lemon.

The Black telescope, also referred to as the Black Moor, is a black variant of the telescope goldfish that has a characteristic pair of protruding eyes.   They are also referred to as popeye goldfish, telescope goldfish, kuro Demekin in Japan, and Dragon Eyes in China.

Bubble Eye goldfish are a small dorsal-less fancy variety that have upward pointing eyes accompanied by two large fluid-filled sacs.

The Fancy Celestial Eye goldfish or Choten gan has a double tail and a pair of upturned, telescopic eyes with the pupils gazing skyward.

The comet small or Comet-tailed goldfish is the most common fancy variety in the United States.   It resembles the common goldfish but it is slightly smaller, slimmer, and can be easily distinguished by its long, deeply forked tail.

The Fantail goldfish is the western form of the Ryukin and possesses an egg-shaped body, a high dorsal fin, a long quadruple caudal fin, and no shoulder hump.

The fancy Lionhead Goldfish has a tremendous hood or head growth with fat cheeks and a turned down tail.   This goldfish is the precursor to the Japanese bred ranchu.

The fancy Oranda is characterized by a prominent bubble like “hood” on the head (also known as wen or head growth) that encases the whole head except for the eyes and mouth.

The fancy Pearlscale or (in Japanese) Chinshurin, is a spherical (golf ball) bodied variety with fins  similar to the Fantail variety.

They can grow to tennis ball size.

The fancy Pompon or Hana Fusa goldfish have bundles of loose fleshy outgrowths between their nostrils, on each side of the head.

The fancy Ryukin is a short, deep body goldfish with a characteristic shoulder hump.  They can be long-finned or short-finned with either a triple or quadruple tail.  The dorsal fin is high and the caudal fin is often twice as long as the body.

The Japanese Shubunkin goldfish is a hardy, single tail variety with nacreous scales and a pattern known as calico.  It is a cross between the Calico telescope eye and the Common goldfish.

The fancy Telescope goldfish is characterized by its protruding eyes. It is also known as the Globe eye or Dragon eye goldfish.

The fancy Ranchu goldfish is a hooded variety that was developed in Japan by crossing different Lionhead goldfish.  In Japan it is referred to as the  “king of goldfish”.

The fancy Panda Telescope is a panda variant of telescope goldfish.  They have the characteristic (Panda) black and white color pattern with telescopic protruding eyes.

The fancy Veiltail goldfish is knwn for its extra long, flowing double tail and it’s sail type dorsal fin.   The hallmark of the breed is it’s long, graceful double tail which is square edged and without any forking or indentation between the lobes.  Modern standards require little to no indentation of the trailing edges of the caudal fins, as in a wedding veil for a bride.

The Butterfly Tail Moor or Butterfly Telescope is twin tailed variety of goldfish that when viewed from above resembles the spread of a butterfly’s wings.

The Meteor goldfish is a strange looking variety that was developed by specialist breeders to have no tail fin, hence its name.  Despite the lack of a caudal fin, the other fins are elongated and it is said to swim surprising well.

The Lionchu or Lionhead Ranchu goldfish is a result of crossbreeding Lionhead goldfish with Ranchus.

The Egg-fish goldfish is a fancy goldfish that lacks a dorsal fin and has a pronounced egg shaped body.  The Phoenix is a Chinese variety of the Egg-fish that also has an egg shaped body and a long tail, without a dorsal fin and no head growth.   Both varieties are bred in all shades of color and scale types.

The Shukin goldfish is Ranchu like variety that was developed in 19th century Japan from the Oranda varieties.   It’s body is shaped like a long Ranchu and it’s tail is long like the Oranda.  They come in red, red and white, white, blue, and silver.

The Curled-gill or Reversed-gill goldfish is an uncommon variety that has was developed by specialist breeders.  Although it resembles a Ryukin, it’s name is derived by the unusual out turned appearance of its gill covers.

The Tamasaba or Sabao goldfish is a rarer Japanesevariety that has a body shaped similar to the Ryukin with a very long, flowing, single tail that resembles a mackerel’s tail, hence its other common name, Mackerel Tail.

The Tosakin or Curly fantail goldfish is a very distinctive breed with a large tail fin that spreads out (like a fan) horizontally behind the fish.
Although it technically has a divided tail, the two halves are attached at the center, in the middle to form a single fin.

Goldfish are a peaceful, gregarious species that often display schooling behavior and are able to thrive in a wide variety of environmental conditions.  They  are suitable for cooler water community aquariums, small water gardens, and outdoor ponds.

The only time they ever display any type of combative behavior towards each other is when they are competing for food.   For this reason, it is recommended that only breeds with similar body types and swimming characteristics be kept together.

Mixing faster swimming breeds like Comets, with slower swimming variants like Pearlscales, can lead to stunted growth or starvation, especially in ponds and water gardens.   The faster fish will quickly eat all the food before the slower swimming species can get to it.

Goldfish are best kept in large aquariums, water gardens, and ponds of at least 180 gallons or larger.  They do best with a gravel substrate, river rocks, and cold hardy plants.   When using a fine gravel or sandy substrate, place some large rocks around the base of the plants to protect their roots from being dug up by the fish.  Goldfish will eat the roots of plants and love to dig around in the substrate.

All goldfish are messy and expel copious amounts of waste, so adequate filtration is necessary to maintain proper water quality.

Goldfish are relatively easy to breed.  Generally before goldfish will begin to spawn,  the water temperature needs to drop down to 64*F for up to a 4 month period.   After 4 months at 64 degrees F, a slow warming of the water to 70-74 degrees F will trigger the spawning process.

The Male goldfish will endlessly chase the female around the tank until she tires out and releases her eggs (up to hundreds of thousands)  all over the tank.   Most of the eggs will adhere to the plants in the breeding tank or pond and the male will spray his milt over the eggs.  The tank or pond water will turn milky from the milt and in about 3 to 4 hours the spawning should stop.

Remove the fertilized eggs from the tank or pond, and place them into a separate 3 to 5 gallon rearing tank with heater, an air powered sponge filter, and not more than 6 inches of water.  Too much water makes it difficult for the fry to swim to the surface.

At 70 degrees F. the eggs will hatch in about 5 days.  At 65 degrees F. it will take 7 days for the eggs to hatch.  Remove all the white and fungus covered eggs from the tank.  Healthy eggs will be transparent in color.  After four days you should be able to see a small black dot inside the goldfish eggs and around the 7th day, the fry will emerge from the eggs and stick to the plants in the tank.  After 3 more days the fry will be free swimming.

The fry can be fed micro worms, crushed hard boiled egg yolk, finely crushed omnivore flakes, liquid fry food, or frozen baby brine shrimp.  Feed the fry three times a day, with as much as they can consume without fouling the water.  The fry grow quickly and should be transferred to “growing” tanks as they outgrow their surroundings.

In the wild Goldfish are opportunistic feeders and will forage on insects, crustaceans, and a variety of plant matter.   They do not stop eating on their own accord and domestically bred goldfish can actually gorge themselves to death.  When you spot a fish with feces trailing from the fish’s cloaca, it is being overfed and they are producing more waste than their intestinal tract can digest.

Goldfish flakes have less protein and more carbohydrates than conventional fish foods and should be provided as a staple with occasional supplements of bloodworms, blanched leafy vegetables and peas with the shells removed.  Young goldfish will also benefit from fresh live or frozen brine shrimp.

Wild Goldfish (Carassius auratus)

Minimum Pond Size: 180 gallons
Care Level: Easy
Temperament: Peaceful
Aquarium Hardiness: Hardy
Water Conditions: 36-90° F, KH 2-12, pH 6.8-7.2
Max. Size: 18″
Color Form: Orange, Red, White, Black
Diet: Omnivore
Compatibility:  Community tank or pond
Origin: China
Family: Cyprinidae
Lifespan: 30 years
Aquarist Experience Level:  Beginner

The Celebes Rainbow (Marosatherina ladigesi) formerly Telmatherina ladigesi, is a species of sailfin silverside endemic to the Island of Sulawesi (Celebes) in Indonesia and is found only near the town of Maros.    They are also known to tropical fish keeping enthusiasts as the Celebes Rainbow Fish, Celebes Sailfish, and Celebes Sailfin.

The Celebes Rainbow can be found in clear, slow flowing, fresh to slightly brackish water streams and estuaries in areas with high levels of dissolved oxygen where they spend a good portion of the day hiding among the leaves of plants eating insects, small worms, vegetable matter, etc.

Celebes Rainbow (Marosatherina ladigesi)

The Celebes Rainbow fish is a peaceful, slender, almost transparent schooling species that has a blue stripe that runs along the lateral line of the body.   Males are larger, darker colored than females, and have more elongated black colored, second ventral and dorsal fins.

Celebes Rainbow fish can be housed with other peaceful shoaling species in at least a 20 gallon aquarium that is densely planted with a sandy or fine gravel substrate, some smooth river rock, a few pieces of driftwood, and plenty of free swimming space.

Some good tank mates include other hard water species such as similarly sized rainbow fish, live bearers, and smaller freshwater gobies. Like many rainbow fish they can be skittish and should be kept in small shoals of at least 6 to 8 of their own kind, preferably in a ratio of 2 to 3 females for every male.

Natural lighting intensifies their colors, as does a dark substrate, but floating plants should be included to provide them with the dimly lit conditions they prefer.  High water quality is essential to the well being of this species, so weekly partial water changes are recommended. Because they are so sensitive to water conditions, an “aged”, well aerated aquarium with good filtration is mandatory.

The Celebes Rainbow is an egg scatterer that will drop their eggs among fine leaved plants, Java Moss, or in nylon spawning mops. Their breeding tank should be at least 18 inches long and filled with aged, slightly hard, alkaline water, kept at a pH of 7.5 and a temperature of around 72-74°F. No substrate is needed with the plants, moss or spawning mops but a small air powered sponge filter should be added for oxygenation and water flow.

Condition a group by feeding them live or frozen food, select the best looking pair, and place them into the breeding tank.  Drop the water temperature a couple of degrees and spawning activity should commence.   The pair will continue to lay several batches of eggs attached by a small thread to the Java moss or spawning mops daily, for a period of several weeks or more. Depending on the water temperature, the eggs will usually hatch within 5 to 10 days and the fry will be free swimming shortly thereafter. After spawning, either remove the parents from the spawning tank or remove the plants or mops to a rearing tank to prevent the parents from eating their eggs.

Initially, the minute fry should be fed infusoria for a week or so until they are able to consume freshly hatched baby brine shrimp, daphnia
, or finely crushed flake food. The fry will remain at or near the water surface, so crushed floating foods are recommended over sinking varieties.

The Celebes Rainbow is an omnivore that has a large mouth but a small throat. They eagerly eat a diet of fresh, frozen, or freeze dried bloodworms, brine shrimp, tubifex, or Spirulina in addition to a quality omnivore flake food. Several small feedings a day are recommended in lieu of feeding single large portions.

Wild Celebes Rainbow populations have been dramatically reduced because of pollution and over harvesting for the ornamental tropical fish keeping hobby however, European and Far Eastern farm bred specimens are readily available online and from specialty tropical fish keeping shops at sizes from 1-1/4″ to 2″.   Wild caught specimens are seldom if ever available for purchase.

Celebes Rainbow (Marosatherina ladigesi)

Minimum Tank Size: 20 gallons
Care Level: Easy
Temperament: Peaceful
Aquarium Hardiness: Relatively Hardy
Water Conditions: 72-82° F, KH 10-25, pH 7.0-8.0
Max. Size: 3″
Color Form: Black
Diet: Omnivore
Compatibility: Peaceful Community
Origin: Indonesia
Family: Atherinopsidae
Lifespan: 3-5 years
Aquarist Experience Level: Beginner/Advanced

The Red Fin Shark (Epalzeorhynchos munense) is a rare species of cyprinid fish found in the Mekong, Chao Phraya, and Mae Klong rivers basins in Indochina that closely resembles the Rainbow Shark (Epalzeorhynchos frenatum).

The Red Fin Shark was named for the Menam Mun River at Tha Chang, East of Korat in eastern Thailand from where it was first collected, and unlike the Rainbow Shark, it is rare in the aquarium trade and has not been commercially bred in Southeast Asian farms.   Specimens have been recorded from some other tributaries of the middle Mekong in both Thailand and Laos, and may occur in Cambodia as well.

The Red Fin Shark is a benthopelagic species that is usually found among boulders and rocks in flowing rivers and streams for most of the year, but are known to move into seasonally inundated floodplains and forested areas during the rainy seasons.

Red Fin Shark (Epalzeorhynchos munense)

The head, body and anal fin of the Red Fin Shark is black.   They have bright red caudal fin and dorsal fins, and black margins on the red pelvic and pectoral fins.   This species also has 11 to 12 branched dorsal-fin rays, and 26 to 30 gill rakers on anterior side of the first arch.

A local variety found in the Mun/Moon river, a tributary of the Mekong in eastern Thailand, has a brown body with a black dorsal fin edged in white, and a white caudal fin.

The unique combination of a black head, body, and anal fin, red caudal and dorsal fins, and black margins on the pelvic and pectoral fins distinguish the Red Fin Shark from the Rainbow Shark (Epalzeorhynchos frenatum).

The two can also be differentiated by the position of their dorsal and pelvic fins.   In Epalzeorhynchos munense, the dorsal base starts ahead of the pelvic fins. In

Albino Redfin Shark (Epalzeorhynchos munense)

Epalzeorhynchos frenatus, the dorsal base is just about in line with the pelvic fins.

Unfortunately, the two species are cross named in tropical fish keeping shops and unless both fish are in hand, they can be difficult to identify.

Fortunately, both species have the same temperament and grow to about the same size. Both become more aggressive as they grow, and although E. munense grows to a little over 9″ long in the wild, both rarely grow more than 3″ or 4″ long in an aquarium environment.

The Red Fin Shark is antagonistic towards their own kind or fish that are similar in appearance.   They are best kept as a single species, one fish per tank. As juveniles, they can be housed with most peaceful species in a community tank, but as they grow larger, they become highly territorial and are best kept with other, like sized medium aggressive fish.   Barbs, larger gourami, danios, and various SouthEast Asian catfish species are all good candidates.   Avoid mixing them with other shark like looking cyprinids.

The Red Fin Shark is best kept in a moderately planted 55 gallon aquarium with a coarse sand or medium size gravel substrate, some rocks and driftwood for them to hide among, and a good filtration system that provides good circulation and a high dissolved oxygen content to the water.   They prefer subdued lighting, a pH of 6.8-7.5, a constant temperature, and a minimum (less than 10 ppm of nitrate, no ammonia or nitrite) of nitrogenous waste.   A tightly fitting cover is also necessary as these species can be jumpers.

Like most minnows, the Red Fin Shark is an egg scatterer as well as an egg eater.  They have not yet been bred in an aquarium environment but they have reportedly been bred through gonadotropic hormone injection.   After scattering up to several hundred eggs and milt, the pair should immediately removed from their eggs.  Any uneaten fertilized eggs will hatch out in a day or so at 80 F.    The fry are free swimming in another day and can be fed newly hatched brine shrimp and finely ground flake foods.

In the wild, the Red Fin Shark feeds on on phytoplankton and zooplankton.  Being largely herbivorous, they eat copious amounts of algae and vascular aquatic plants by grinding them with their pharyngeal teeth. In an aquarium environment, they should be fed spirulina wafers, algae wafers, sinking pellets and some meaty foods in the form of frozen or freeze dried bloodworms or tubifex.

The Red Fin Shark is a rare find for tropical fish keeping enthusiasts and specimens when available are almost always caught in the wild.   Misidentified specimens are occasionally imported and mixed in with other “shark minnows” as juveniles.

Red Fin Shark (Epalzeorhynchos munense)

Minimum Tank Size: 55 gallons
Care Level: Moderate
Temperament: Semi-aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-79° F, dH 2-15, pH 6.8-7.5
Max Size: 9″
Color Form: Black, Red
Diet: Omnivore
Compatibility: Single species peaceful community tanks
Origin: Thailand, Laos, Cambodia
Family: Cyprinidae
Life Span: 4-6 years
Aquarist Experience Level: Intermediate

The Rainbow Shark (Epalzeorhynchos frenatus) is a popular semi aggressive aquarium species known to tropical fish keeping enthusiasts as the Ruby Shark, Red-Finned Shark, Red-Fin Shark, Rainbow Sharkminnow, Green Fringelip Labeo, Whitefin Shark and Whitetail Sharkminnow.

Rainbow Sharks are native to the Mekong, Chao Phraya, Xe Bangfai and Maeklong river basins in Indochina where they are most commonly found over sandy substrates along the bottom of rivers.

Rainbow Shark (Epalzeorhynchos frenatus)

The Rainbow Shark is a beautifully colored fish that has an elongated dark blue gray to black body, or a bright blue body and red, to orange red fins with a pointed snout.

The abdominal area is flat, and there is a short dark stripe that starts at the mouth of the fish, goes through the eye and ends at the gill cover. Their colors become more intense as they mature.

Albino Rainbow Shark (Epalzeorhynchos frenatus)

There is a well known color variation of the Rainbow Shark called the Albino Red Fin Shark or Albino Rainbow Sharkminnow.

This variant has a white body and red to orange fins and is almost identical to the Rainbow Shark in temperament and appearance.

Male Rainbow Sharks have thinner bodies than the females, black lines along the tailfins, and are more vividly colored.

Epalzeorhynchos munense is a separate species that rarely enters the aquarium trade and is commonly confused with the Rainbow Shark (Epalzeorhynchos frenatus).

The Rainbow Shark is great for a semi-aggressive community aquarium, provided they are the only shark in the tank, and their tankmates are of similar size.   Rainbow sharks are compatible with Barbs, Rainbowfish, Danios, Loaches, Plecos, Rasboras, and Gouramis.   They are not compatible with smaller, more timid fish which they will dominate and terrorize.

Rainbow Sharks are best housed in a densely planted aquarium of at least 55 gallons, with a sandy or fine gravel substrate, rocks, some driftwood, and plenty of swimming space.   Sharks will usually stake out territories in an aquarium and become very aggressive towards others of their own species.

Rainbow Sharks are egg layers and although large quantitie are commercially bred in Southeast Asian fish farms, no breedings have been documented in an aquarium environment.

In their natural habitat, Rainbow Shark are omnivores that feed on algae and plankton along sandy river bottoms.   They migrate into flooded areas during the rainy seasons and back into the rivers as the floods recede.   In an aquarium environment, they are not picky eaters and will readily accept flake foods as well as live, frozen, or freeze dried bloodworms, tubifex, and vegetable based foods.

The Rainbow Shark is readily available to tropical fish keeping enthusiasts at an approximate purchase size of 1-1/4″ to 2″.

Rainbow Shark (Epalzeorhynchos frenatus)

Minimum Tank Size: 55 gallons
Care Level: Moderate
Temperament: Semi-aggressive
Aquarium Hardiness: Hardy
Water Conditions: 75-81° F, KH 10-15, pH 6.5-8.0
Max Size: 6″
Color Form: Black, Red
Diet: Omnivore
Compatibility: Not suitable for peaceful community tanks
Origin: Indochina, Farm Raised, Thailand
Family: Cyprinidae
Life Span: 4-6 years
Aquarist Experience Level: Intermediate

The Scarlet Livebearer (Micropoecilia picta)  is a highly sought after, brackish water guppy species known to tropical fish keeping enthusiasts as the Swamp Guppy, Painted Guppy, or Barrigudinho Guppy.  They are distributed throughout Central and South America, from Trinidad to the Amazon River Delta countries of Brazil, French Guiana, Guyuana, and Trinidad Tobago.

Scarlet Livebearers are found in the mildly brackish water marshes, swamps, drainage ditches, and canals of their range where they primarily feed on mosquito larvae, small crustaceans, algae, and plant foods.

Scarlet Livebearer (Micropoecilia picta)

Scarlet Livebearers have a striking red to orange body color that is dramatically accented with black markings, making it a highly desirable species.   Males are smaller and have a base body color that ranges from silver and green with black, yellow and blue spots to a red base color with yellow and black spots.

Male Scarlet Livebearers are also more slender and brightly colored than females, and have a gonopodium.   Females are larger, fuller bodied, and have a silver base color with some gold points or orange around the abdomen.   Like female Poecilia reticulata, they develop a spot during pregnancy.

Micropoecilia picta prefer hard, slightly brackish, alkaline water conditions and are prime candidates for a biotope aquarium setup.  They can be kept in fresh water with a slightly alkaline pH of medium hardness, but they thrive in brackish water.  They cannot tolerate soft, acidic water conditions.

The Scarlet Livebearer should be housed in a densely planted tank of at least 20 gallon capacity with a sandy or fine gravel substrate that already has some growing algae and plenty of swimming space

Large tall salt tolerant plants and a couple of pieces of bogwood will finish the setting and help bring out their colors.   A minimum of one teaspoon of aquarium salt per gallon of aquarium water is recommended to keep these fish healthy, and a bright “grow” light is suggested to enhance their rich iridescent colors and to promote algae growth.

Scarlet Livebearers are an active, extremely peaceful species that spend most of their time at or near the waters surface.  But, because they constantly harass females, it is recommended to keep at least three females to each male in a single species tank.   They are a shoaling species that do best with others of their own kind, and at least 8 to 10 should be placed together in a biotope system.

Tank bred specimens can be housed with Endler’s Livebearers, Rainbowfish, Danios, small Gouramis, and other small to medium size aquarium fish that are salt tolerent in a community setting but a slightly brackish biotope setting is recommended.

Black Livebearer (Micropoecilia picta) Pair

As their name implies, the Scarlet Livebearer is a Viviparous species.   Their fertilization is internal and their reproduction is similar to Poecilia reticulata.

When the female is able to reproduce, a spot develops on her abdomen and the male uses his gonopodium to fertilize the female.  The fry are able to swim freely immediately after being expelled from the female and are able to eat shortly thereafter.

Ideally, the breeding tank should be thickly covered with floating plants and a breeding box to protect the fry.  If left to fend for themselves, the fry will be eaten by the adults.  The fry can be fed baby brine shrimp, , or finely crushed omnivore flakes almost immediately after birth.

Adult Scarlet Livebearers are omnivores that require algae in their diet along with live, frozen, or freeze dried meaty foods like bloodworms, mosquito larvae, tubifex, etc.

Smaller than Poecilia reticulata and a slightly less prolific breeder, the Scarlet Livebearer is rarely available to tropical fish keeping enthusiasts.   When available they are usually 0.75″ to 1″ in length and demand a premium price.

Their continued lack of availability in the aquarium trade and their dramatic coloration continue to make the Scarlet Livebearer one of the most highly sought after species of guppy.

Scarlet Livebearer (Micropoecilia picta)

Minimum Tank Size: 20 gallons
Care Level: Easy
Temperament: Peaceful
Aquarium Hardiness: Relatively Hardy
Water Conditions:  64-82° F, dH 20-40, pH 7.5-8.2
Max. Size:  1″
Color Form:  Black, Red
Diet: Omnivore
Compatibility:  Single species tank
Origin:  South America
Family:  Poeciliidae
Lifespan: 2-5 years
Aquarist Experience Level: Advanced

The Fancy Guppy (Poecilia reticulata) is also known to tropical fish keeping enthusiasts as the rainbowfish, missionary fish, millionfish, or mosquito fish.   Although it is widely distributed throughout the world and is arguably one of the most popular freshwater fish of all time, it’s natural range is in northeast South America

The Common Guppy (Poecilia reticulata) has two other relatives in the Poeciliidae family; Poecilia wingei (the Endler guppy), and Micropoecilia picta, the smallest member of the guppy family that is found in brackish waters.

Wild Guppies can be found in the wild in Antigua, Barbados, Brazil, Guyana, Jamaica, the Netherlands Antilles, Trinidad and Tobago, the U.S. Virgin Islands, and Venezuela and have been introduced into many different countries for the purpose of mosquito control, hence the name mosquito fish.

The common Guppy is a highly adaptable species that can survive and thrive in a variety of relatively “harsh” environments.  They are found in almost every freshwater body of water accessible to them, but prefer smaller streams and still pools rather than large, deep, or fast flowing rivers. Because of their high tolerance to salt water, they have also populated brackish water Estuaries.

In their natural environment, common Guppies feed on both animal and vegetable matter; primarily small insect larvae, small crustaceans, and benthic algae.

Male guppies are always much smaller than females, however their dorsal, anal, and caudal fins are usually much longer and colorful.  Female guppies are usually much larger, drab in color, and lack the ornamental fins that adorn the males.  Wild caught Guppies are much less colorful than their domestically bred counterparts however, through selective breeding, many unique color strains, body color patterns, and caudal fin types have been developed over the years to provide tropical fish keeping enthusiasts a plethora of choices for stocking peaceful community aquarium.  These strains are generically called Fancy Guppies.

Fancy Guppies are available in every color combination of the rainbow, as well as different body patterns and tail types.   Guppy breeders are constantly working on creating new varieties, and because of the limitless variations that can be bred, it is practically impossible to describe every variety here.   Instead we will try to identify some of the more popular varieties available to tropical fish keeping enthusiasts.

Types Of Guppies

Three characteristics are used to distinguish Fancy Guppy strains.

• Color (Body and fins which are often different)
• Pattern (Body and tail patterns frequently vary)
• Fin types (Delta, Round, Lyretail, etc.)

Fancy Guppies are bred in every conceivable color of the rainbow including albino, iridescent, and metallic varieties.  Their colors can be solid, split on the upper and lower portions, split on the front and rear portions, or mixed.   Except for the albino, gold, and platinum strains, the head and main body colors are usually lighter and in many strains, the posterior portions of the body closer to the caudal fin, is sometimes differently colored.

Fancy Guppy body patterns can be broken down to three or four types.

• Cobra
• Snakeskin
• Tuxedo
• Solid

Cobra body patterns exhibit rosettes as well as some vertical barring.
Snakeskin body patterns have a chain like look across the base body color. Some strains have rosettes.
Tuxedo body patterns have the front half of the body one color, and the rear half a different color. Light colored upper bodies and a darker lower body color also distinguish Tuxedo strains.
Solid body color strains are also available and except for true albinos, are actually more difficult to obtain.

Fancy Guppy caudal fins can be a solid color, or patterned.  The most common patterns are Grass, Lace, Leopard, and Mosaic.

Grass pattern tails are made up of a series of fine dots that cover the base color and are said to resemble grass seeds.
Lace pattern tails have a web like appearance.
Leopard pattern tails cover the fin with a series of spots that vaguely resemble those of a leopard.
Mosaic pattern tails are made up of an irregular pattern of connected spots.

Guppy breeders have developed several different tail types over the years, most of which are listed below:

Bottom swordtail
Cofer Tail (Spade Tail)
Delta Tail (Triangle Tail)
Double sword Tail
Fantail
Lyretail
Pintail (Needle Tail)
Ribbon
Roundtail
Scarf Tail (Flag Tail)
Speartail
Swallow
Top swordtail
Veiltail

The above tail types often go by different names in different areas of the world, which can lend to some confusion in identification.   The pictures however are self explanatory.

Most Fancy Guppies have black eyes however, there are two types that have red eyes.  The true albino guppies that lack melanin and have paler red eyes, and the so called Real Red Eye guppies which are colored normally, but have red eyes.  The latter are usually smaller than the strains with normal colored eyes.

If you think about all the possibilities when you mix these characteristics, you can understand why it is impossible to describe all the strains available to tropical fish keeping enthusiasts and why only a small fraction of fancy guppy varieties are ever sold in tropical fish shops.

As you might guess, Guppies are highly prolific breeders and one of the easiest to breed species; perfect for beginning tropical fish keeping enthusiasts.   These colorful fish are live bearers and can be bred in a community tank or in the case of Fancy Guppies, in separate tanks to create a new strain or keep an existing strain pure.

Although they are hardy, quite adaptable, and can breed in almost any type of water conditions, the breeding tank water should be kept between 74 and 82°F.

When a well conditioned pair or trio is placed together and ready to spawn.   A male will approach the female from below, extend his gonopodium, and inseminates the female.   If mating is successful, the female guppy can store the sperm from a single male for up to 3 months and give birth to up to three spawns from one coupling.   This is important if the breeder is trying to develop a new strain or maintain the current strain.

If a new color strain, body pattern, or fin type is trying to be developed, the female should be kept isolated for at least 3 spawns to allow all the sperm to be used up before introducing another male.

When the female is pregnant, her belly will become rounded and quite large.   A dark gravid spot will appear on her belly near the anal vent which is actually the fry developing.  Immediately before birth, the tiny eyes of the fry can be seen through the skin of the female’s body.  During this period she should be left alone to reduce any stress which could cause her to either absorb the fry or have a premature birth; either of which could kill the fry.

When birthing occurs, individual fry are dropped in sequence over a period of up to eight hours.

Although the gestation period for the common guppy is usually around 28 days, they can give birth anywhere from 20 and 40 days after mating.   And, depending on the size and age of the female, anywhere from 20 to 200 fry can be produced per spawn.

After the female gives birth, the fry should be provided with plenty of Java Moss, Water Sprite, Water Wisteria, Duckweed, or other dense cover for them to hide and escape from being eaten.  Although, well fed adults seldom eat their young, it’s a good idea to remove the parents from the breeding tank after spawning.

The fry can be fed newly hatched baby brine shrimp, liquid fry food, microworms, infusoria, vinegar eels, finely crushed or powdered flake food, or Daphnia almost immediately after being born.   Avoid overfeeding and make frequent 25% water changes to keep pollution in the tank to a minimum.

Guppy fry grow quickly and only take about three to four months to reach maturity.  Within a couple of months you should be able to determine the sex of the fry.

The Fancy Guppy (Poecilia reticulata) has been successfully hybridized with various molly species (Poecilia latipinna or Poecilia velifera) using a male guppy and a female molly, however, the hybrids are always infertile males.   Guppies have also been hybridized with the Endler’s livebearer (Poecilia wingei) which produce fertile offspring.

Guppies are the perfect “starter fish” for beginning tropical fish keeping enthusiasts the world over.   They are peaceful, colorful, inexpensive, easy to keep, and tolerant of varied water conditions.   Although they prefer a hard water aquarium, temperatures between 78 and 82 °F, and a salt level equivalent to one tablespoon per 5 gallons of fresh water, they are able to tolerate salt levels up to 150% of normal seawater.

In the wild, Guppies are usually collected from large groups or shoals and should not be kept alone in an aquarium environment.   They lend towards nipping the fins of fish with long flowing fins and with other males, but they normally don’t do much damage.  In general, they make a colorful addition to any peaceful well planted community tank.

Adult Guppies are easy to feed and should be provided with a mixed diet of live, frozen, or freeze dried Daphnia, brine shrimp, tubifex, or bloodworms along with a quality flake food.

A plethora of Fancy Guppies varieties are readily available online from wholesalers, importers, breeders and at almost every tropical fish keeping retailer in the country.  Prices can vary greatly and are dependent on color strain, body and fin pattern, quality, rarity, etc.

The Round Tailed Paradise Fish (Macropodus Ocellatus) is also known to tropical fish keeping enthusiasts as the Chinese Paradise Fish and is found throughout China, Korea, Japan, and probably northeastern Vietnam between the Zhu Jiang (Pearl River) in southern China and the Heilong Jiang (Amur River) at the northeastern China, Russian border.   There are also populations in the Russian portion of the Amur basin which are believed to have been artificially introduced.

Round Tailed Paradise Fish are frequently collected from irrigation ditches, marshes, rice paddies, pools, streams, and slow moving backwaters of larger rivers.

This species is extremely adaptable and during the winter months, temperatures across some of its natural range often drop well below zero, resulting in frozen water surfaces and water temperatures as low as 37°F.   They thrive in colder, still or slow moving water with dense vegetation and can be seen swimming under the ice in some parts of their range.

Round Tailed Paradise Fish (Macropodus Ocellatus)

Unlike other species of paradise fish, Macropodus ocellatus has a round, red tail with white flecks.   The body is colored a charcoal grey with white stripes on the head.

They have enormously extended dorsal and anal fins that are colored red and yellow.   The tips of these fins can go well beyond the end of their caudal fins.

The eye stripe is a not connecting spot on the posterior projection of the opercle with the eye and the posterior tips or margins of their body scales are not any darker than the color of the scales.

Males are larger than females, have much darker colors, and possess extended soft rays in their dorsal, anal, and caudal fins.   Females are more of a beige color and have shorter fins, but are otherwise similar in appearance to the males.

Round Tailed Paradise Fish behave identically to Macropodus Opercularis, except that they are slightly less aggressive to their own kind and prefer cooler water temperatures.   Several specimens can be kept together as a group in a large aquarium without incident but kept alone, it is not a trustworthy candidate for a community tank.   When choosing tank mates, it is important to keep in mind the lower temperatures that these fish require. Keeping them in pairs or small groups is the preferred option.

Macropodus ocellatus are best kept in a densely planted, 30 gallon or larger aquarium with a fine gravel substrate, some rock work and/or driftwood for them to hide among, and some floating plants.   The water temperature in the tank should not exceed 75 degrees F. and their tank should be allowed to cool down to around 50 degrees F. for several months of the year to mimic their natural habitat.

Round Tailed Paradise Fish are bubble nest builders and can be bred in the same manner as Macropodus Opercularis.   Soft water with a slightly raised temperature is said to induce spawning activity and a tightly fitting cover for the tank is necessary to create a layer of warmer humid air that is necessary for the development of the labyrinth organ in the fry.

When a conditioned pair is ready to breed, the male will construct a bubble nest among the surface vegetation. The female is normally tolerated during the building of the nest and once the nest is complete, the male will entice the female by displaying his elongated dorsal, anal, and caudal fins.

The female will become paler and the typical spawning “embrace” commences under the nest.   The male wraps his body around the female until some milt and a few eggs are released.  The eggs contain a globule of oil which allows them to float upwards into the nest however, the male will usually help out the process by gathering the fertilized eggs into his mouth and placing them in the bubble nest.   The process is repeated several times until the female is spent and several hundred eggs are deposited into the nest.

After spawning is completed and as long as sufficient cover is provided, the female can be left in the tank to help guard the eggs.   The eggs will hatch in 3 to 4 days and the fry will remain in the nest until their egg sacs are absorbed and they become free swimming.   At this point the adults should be removed from the breeding tank and the fry should be fed infusoria until they are able to accept microworms or newly hatched baby brine shrimp. Frequent small water changes should be performed during the rearing process.

Because of their extreme tolerance to cold, Round Tailed Paradise Fish are often kept in ponds throughout the world.   It is important not to release them into the wild as they could easily survive, breed, and become a potential invasive species.

In their natural habitat, Round Tailed Paradise Fish prey on insect larvae, small crustaceans and small fish.   In an aquarium environment, they will eagerly accept live, frozen, or freeze dried Daphnia, brine shrimp, white worms, tubifex and a quality omnivore flake food.

Macropodus Ocellatus are a strikingly beautiful species that are rarely available to tropical fish keeping enthusiasts.   They are sometimes available online from importers and European breeders and are moderately priced.

Round Tailed Paradise Fish (Macropodus Ocellatus)

Minimum Tank Size: 30 gallons
Care Level: Easy
Temperament: Mildly Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 50-72° F, 6-10 dKH, pH 6.0-7.5
Max Size: 3.1″
Color Form: Gray, Beige
Diet: Omnivore
Compatibility: OK community tank
Origin: Asia, Russia
Family: Osphronemidae
Lifespan: 3-5 years
Aquarist Experience Level: Intermediate

Black Paradise Fish (Macropodus spechti) are found in central Vietnam in the Thu Bồn River system in Quảng Nam province and the Hương (Perfume) River basin in Thừa Thiên-Huế province.   Like other Paradise Fish species, they inhabit rice paddies, irrigation ditches, small pools, marshes, densely vegetated hill streams, and the backwaters of larger rivers in their range.

Black Paradise Fish (Macropodus spechti)

The Black Paradise Fish has a forked caudal fin and either lacks the dark bars on the body entirely, or has 4 to 12 very faint, inconspicuous dark bars on a pale brown to dark gray background on the body.

The dorsal surface of the head and predorsum does not have the dark spots or saddle like blotches of other species and the rear tip or margin of the scales on the head and body are noticeably darker than the scales themselves.

Unlike the similar looking Macropodus erythropterus which is easily identified by its reddish pigmentation on the dorsal, anal and caudal fins, Macropodus spechti have the distal portion of their anterior soft pelvic fin ray red with black spots and bars on the dorsal and caudal fin membranes, posterior dorsal fin membranes, and the caudal fin membranes being blue.

The filamentous caudal fin rays have a white or black posterior extremity with no red pigmentation in the unpaired fins.  Males are generally larger than females and have extended soft rays in their dorsal, anal, and caudal fins.

Macropodus spechti, like other gourami species possess a labyrinth organ that allows the fish to breathe atmospheric air and survive in harsh water quality environments that would kill other species.

Black Paradise Fish are best kept in a densely planted 30 gallon or larger aquarium with a sandy or fine gravel substrate, some driftwood arranged to provide shady areas for them to hide among, some floating plants, and a layer of dried Indian Almond Leaves to mimic their natural environment.  The leaf litter develops beneficial microbe colonies as the leaves decompose which become a valuable food source for the fry.

Like most gourami species, Macropodus spechti are bubble nest builders and are relatively easy to spawn.

Spawning can be induced by providing soft water in the breeding tank, lowering the water level to about 6″ and slightly raising the water temperature.

Black Paradise Fish do not need to be separated prior to breeding. The male will build a bubble nest among vegetation at the surface and will usually tolerate the female during this period. When the nest if completed, the male will “court” the female by displaying this elongated dorsal, anal and caudal fins until she show interest in spawning.

Spawning occurs under the bubble nest in the typical embrace with the male wrapped around the female. As the eggs and sperm are simultaneously released into the water column, the male will collect any fertilized eggs that do not float to the surface of the nest and place them there before continuing the mating ritual. Typically, several hindered eggs will be released into the nest before the female is spent and spawning is completed.

Unlike some other species, the female is tolerated by the male after spawning and often helps guard the bubble nest.

When the eggs hatch and the fry have absorbed their egg sacs, they can be fed infusoria for the first few days until they can accept freshly hatched baby brine shrimp or . During this period frequent small water changes should be made and a tight cover should be placed on the rearing tank to ensure that the labyrinth organs in the fry develop properly. Although the parents usually do not eat their offspring, many breeders remove both parents to ensure a high yield.

Black Paradise Fish prey on mosquito larvae, insect larvae and small fish in their natural environment. In an aquarium environment, they will eagerly accept live, frozen, or freeze dried Daphnia, white worms, grindal worms, brine shrimp, tubifex, etc. along with a good quality omnivore flake food.

Black Paradise Fish are not common in the aquarium trade but are occasionally available from importers or breeders online at a modest cost when they are 1 1/2″ to 2 1/2″ in size.

Black Paradise Fish (Macropodus spechti) Pair

Minimum Tank Size: 30 gallons
Care Level: Easy
Temperament: Peaceful
Aquarium Hardiness: Hardy
Water Conditions: 68-86° F, 5-20 dKH, pH 6.0-8.0
Max Size: 3″
Color Form: Black, Gray
Diet: Omnivore
Compatibility: OK community tank
Origin: Vietnam
Family: Belontiidae
Lifespan: 5-8 years
Aquarist Experience Level: Intermediate

Paradise Fish (Macropodus opercularis) are a species of Gourami that is found throughout East Asia, from the Korean peninsula to North Vietnam.   There are a number of species of Paradise fish known to tropical fish keeping enthusiasts but the most common are Macropodus Opercularis, Macropodus Ocellatus, and Macropodus Spechti.   Of the three, Macropodus opercularis is by far the best known species seen in western tropical fish shops.

All Paradise Fish frequent the marshes, irrigation canals, ditches, rice paddies,  and other shallow densely vegetated waters throughout their range where they feed on insects, invertebrates, and fish fry.

Like other species of gourami, Paradise Fish have a labyrinth organ that allows them to breathe air and survive in stagnant, oxygen depleted waters that would normally kill most other species and in an aquarium environment, they need access to the surface of the tank.

Paradise Fish (Macropodus opercularis)

Paradise Fish are a brightly colored species that were one of the first ornamental fish available to western tropical fish keeping enthusiasts as early as 1869.

They have alternating turquoise blue and orange stripes that extend into their feather like fins and Betta like tail.  There is a spot on the gills and a pattern of dark scales on the head that continues over the back and gradually fades as it goes down the back of the fish.

Males have much longer fins and are more brightly colored than the females.

The Paradise Fish is one of the few species that can change its color in response to stimuli.   Its colors becomes darker and more enhanced during combat or when frightened, or lighter colored at will, and it can also be taught though a type of restrictive learning process.

Paradise fish are a pugnacious, highly territorial species that should only be kept with other large, semi aggressive species.  They will eat smaller tank mates and are as combative as Bettas therefore, only one male should be kept per tank.  They are best housed in densely planted aquarium of at least 30 gallon capacity with a sandy or fine gravel substrate, some smooth rock work and some driftwood or bogwood for them to hide among.   They need adequate filtration with little to no water movement in the tank and because they are great jumpers, it’s a good idea to place a tight fitting cover over their tank.

Paradise Fish can be kept in a community environment with large tetras, some of the less aggressive cichlids (Firemouth Cichlids), Giant Danios, and most of the smaller catfishes.  They can also be kept with significantly larger non-aggressive species, like geophagus cichlids, the larger gouramis, and some of the larger synodontis catfishes.  Slower moving, long finned species like Angelfish, Bettas, or other male Paradise Fish should be avoided.

Like most Bettas and Gourami, the Paradise Fish is a bubble nest builder.   To induce spawning, lower the water level in the spawning tank to about 6″ and increase the water temperature.   When conditions are “right”, the male will begin to construct a floating mat of saliva coated air bubbles under floating vegetation or some other plant matter where the eggs will be held for hatching.

The male will begin to make advances toward the female until she is receptive to his open water embrace where both eggs and sperm are released into the water column.    After each embrace, the male will gather the fertilized eggs into his mouth and deposit them into the bubble nest.    After spawning is complete, as many as 500 eggs may be deposited into the nest where the male guards them until they hatch.

At this point, the female should be removed from the spawning tank or the male will violently attack her and any other fish venturing into the territory of the nest.

When the eggs hatch out and the fry have absorbed their egg sacs, the male should also be removed from the tank.  The tiny fry should be fed infusoria until they are able to eat newly hatched baby brine shrimp or finely crushed flake food on their own.

Paradise Fish are omnivores that require both algae based and “meaty” foods.   Although they will accept virtually any food, they should be given a relatively high protein diet of live, frozen, or freeze dried mosquito larvae, small flies, black worms, brine shrimp, or tubifex along with a quality algae based flake food.

Paradise Fish are usually readily available in most tropical fish keeping shops when they are 1-3/4″ to 2-1/4″ in size.

Paradise Fish (Macropodus opercularis)

Minimum Tank Size: 30 gallons
Care Level: Easy
Temperament: Semi-aggressive
Aquarium Hardiness: Hardy
Water Conditions: 61-79° F, KH 4-18, pH 6.0-8.0
Max Size: 3″
Color Form:  Blue, Orange
Diet: Omnivore
Compatibility: OK community tank
Origin: East Asia
Family: Belontiidae
Lifespan: 5-8 years
Aquarist Experience Level: Easy

Gold Gourami (Trichogaster trichopterus) along with other mutations, are a color variant of Three Spot Gourami (Trichopodus trichopterus) that were developed for tropical fish keeping enthusiasts during the 1970s.   Gold Gourami are also known to tropical fish keeping enthusiasts as the Crosby Gourami after the breeder who developed the morph.   It was further mutated into the Opaline Gourami (Marbled Gourami) and the silver colored Platinum Gourami, which also appeared during the 70s.

Like all gourami, Gold Gourami posses a labyrinth organ that allows them to breathe atmospheric air to survive in stagnant waters with low oxygen content and in an aquarium environment, they should always have access to the surface of the aquarium to take a gulp of air when needed.

Gold Gourami (Trichogaster trichopterus)

Gold Gourami are an elongated, laterally compressed species with long, touch sensitive, threadlike ventral fins that are used to “feel” their surroundings.   Their fins are relatively large and rounded, with males having more pointed dorsal and anal fins than females.

The body color is a pretty gold tone with deeper toned stripe pattern along the back of the fish.   The two dark spots normally seen on Three Spot Gourami are totally absent on this morph and the white spots on the body that extend to the fins give the fish an exceptionally attractive body pattern.

Except for their disposition and their strikingly different gold coloring, Gold Gourami grow to the same size and require the same care as their predecessors.   As juveniles, they make excellent community fish with others of their same size, but their temperament becomes more belligerent as they attain adulthood.  Because they are exceptionally hardy and long lived, they make a great “first fish” for tropical fish keeping enthusiasts new to the hobby.

Gold Gourami are best kept in a densely planted tank of at least 30 gallons with a dark sandy or fine gravel substrate, some rock work and driftwood for them to hide among, and plenty of free swimming space.   They like the cover of floating plants, but they will regularly breath air at the surface, so its important to have some open areas.   They are tolerant of wide range of water parameters but do best with little to no water movement, and an adequate filtration system.

Gold Gourami are bubble nest builders that are relatively easy to breed.   The breeding tank water level should be lowered to about 6″ to 8″ and the temperature should be raised to about 80 degrees F.   The male will build a bubble nest at the surface of the water and when ready to breed will entice the female to spawn by repeatedly swimming back and forth under the nest with his tail raised and fins flared.   The male will wrap himself around the female and fertilize up to 800 eggs during a single spawn.  As the female lays her eggs, the male places them into the nest where he guards them until they hatch.

It is recommend to remove the female from the spawning tank immediately after spawning is completed.   The eggs will hatch within 48 hours and the fry will become free swimming shortly thereafter.   Remove the male from the tank and place a tight cover over the aquarium to ensure the proper development of the labyrinth organs in the fry.  The fry should be fed liquid fry food or infusoria until they are large enough to eat baby brine shrimp.

Gold Gourami are omnivorous and will eat all kinds of live, frozen, freeze dried, and flake foods.   To keep a good balance, give them a quality flake or pellet food as a base diet and supplement it with white worms, blood worms, brine shrimp, or any other suitable substitute.   Blanched vegetables can also be offered occasionally.

Interestingly, Gold Gourami, Three Spot Gourami, and Pearl Gourami are all fond of eating hydra and will quickly rid your system of a hydra infestation in your aquarium.   The hydra is a tiny tentacled, venomous pest that can capture and paralyze tiny fry and very small fish in your aquarium.

Gold Gourami are readily available at most tropical fish shops at reasonable prices when they are 1 1/2″ to 2 1/2″ in size.

Gold Gourami (Trichogaster trichopterus)

Minimum Tank Size: 20 gallons
Care Level: Easy
Temperament: Peaceful to Semi Aggressive
Aquarium Hardiness: Very Hardy
Water Conditions: 72-82° F, KH 4-18, pH 6.0-8.8
Max Size: 6″
Color Form: Gold
Diet: Omnivore
Compatibility: OK community tank fish
Origin: Southeast Asia
Family: Belontiidae
Lifespan: 4-8 years
Aquarist Experience Level: Easy

Pearl Gourami (Trichogaster leeri) are also known to tropical fish keeping enthusiasts as the Leeri Gourami or Lace Gourami, and are native to Thailand, Malaysia, and Indonesia on the islands of Sumatra, and Borneo.

The fish are generally collected in the acidic waters of lowland swamps where they prefer the middle and top levels of the water column.

Pearl Gourami (Trichogaster leeri)

Pearl Gourami have a laterally compressed body with long, thin ventral fins that look and act as feelers.

They are covered with iridescent pearl and brown flecks that give it a “mother of pearl” appearance.  A horizontal black line runs through the length of the body from the lips to the tail where it ends in a spot.

Like most gourami, Pearl Gourami have a labyrinth organ that allows them to breathe air and survive in oxygen depleted waters that would normally kill most other species which is why they need access to the surface of the tank.

Males have more pointed dorsal and anal fins and are colored with more red than the females. Females have a more rounded body shape with rounder dorsal and anal fins.

Pearl Gourami are an ideal community tank fish that can be housed with other peaceful, like sized species or in groups of at least 6 of their own kind. They should never be kept with aggressive species like Cichlids or they will become recluses, lose their beautiful colors, and often refuse food.

Pearl Gourami need at least a 30 gallon densely planted tank with a dark sand or fine gravel substrate, some driftwood or bogwood, plenty of swimming space, and some floating plants that can be used to diffuse light and provide hiding places for the fish.  They do not need a deep tank and do quite well in water that is less than a foot deep.

Pearl Gourami are bubble nest builders that incorporate aquatic vegetation into their nests to bind the bubbles together.  To breed Trichogaster leeri, first condition a pair with live or frozen brine shrimp or bloodworms.  Drop the water level in the breeding tank down to about 8″ and maintain the water temperature at 82 °F and the pH at 7.0.  When ready to spawn, the male will build a bubble nest where spawning takes place.

When the female takes a position under the nest, the male curves his body tightly around her, from underneath. Her body will quiver as she expels a few eggs. The male releases the female, picks up the eggs into his mouth as they are slowly sinking, and then he spits them into the bubble nest.  This scenario is repeated several times until spawning is completed.

After spawning, most breeders remove the female from the tank and the male will guard the eggs and fry until they become free swimming, at which time he should also be removed from the tank.  The eggs will generally hatch within two days and the fry become free swimming three days later.  At this time they can be fed infusoria, liquid fry food or baby brine shrimp until they can accept finely crushed flake food.  This usually takes from 7 to 10 days.  The older fry can be fed freeze dried pellets.

As soon as the fry are mobile, it is important to place a tight fitting cover over the breeding tank and to keep the temperature at 84 degrees to create and maintain the hot, humid environment needed for the labyrinth organs to develop in the fry.  No water movement is necessary but frequent water changes should be made during this stage when infusoria or baby brine shrimp are fed to the young.

Pearl Gourami are omnivores that eat both algae based and meaty foods. In an aquarium environment, they are not picky eaters and will eagerly accept algae based flake foods, live, frozen, and freeze dried mosquito larvae, bloodworms, tubifex, blackworms, and brine shrimp.

Pearl Gourami are a favorite of tropical fish keeping enthusiasts and are available for purchase when they are 1 1/2″ to 2″ in length.

Pearl Gourami (Trichogaster leeri)

Minimum Tank Size: 30 gallons
Care Level: Easy
Temperament: Peaceful
Aquarium Hardiness: Hardy
Water Conditions: 75-86° F, KH 5-18, pH 6.5-8.0
Max Size: 4.7″
Color Form: Clear, White
Diet: Omnivore
Compatibility: Excellent community tank fish
Origin: Borneo, Malaysia, Sumatra
Family: Belontiidae
Lifespan: 5-8 years
Aquarist Experience Level: Easy

The Yo-Yo Loach (Botia almorhae)  is also known to tropical fish keeping enthusiasts as the Pakistani Loach, Reticulated Loach, Y-Loach and Almora Loach.   Although it is named for the district (Almora), Uttarakhand State, India where it is found, it is also called the Pakistani Loach, which is actually a misnomer, since it is restricted to parts of the Ganges River drainage in northern India, and possibly Nepal.    They are found in India, Nepal, and Bangladesh.

Specimens collected from Pakistan are generally a darker color than the India varieties and local color variations are common.

The Yo-Yo Loach is an active, playful fish that is also a great scavenger in a community aquarium.   They are found in the rivers and slow moving highland streams of their range where they tend to congregate in pools and still water areas around rocky substrates.    Prior to spawning, they migrate upstream.

Yo-Yo Loach (Botia almorhae) Juvenile

The Yo-Yo Loach has a silvery to yellowish body color with dark vertical bands.   Juveniles are more brightly colored, and because of the obvious pattern of ‘Y’s and ‘O’s along the fish’s side, the tern Yo-Yo was coined.

The juvenile body markings in this species can be extremely variable, but  as the fish turn into adults, their body pattern fills in and becomes more reticulated, hence another one of their common names.   Females are noticeably plumper than males and when gravid, can actually become extremely fat.   Males can be identified by their slimmer body and redness around the barbels and mouth area.

Botia almorhae are often kept in a group of 6 or more of their own species, or in a community aquarium with other peaceful to semi aggressive species.    They are good community fish and mostly hide during the day, coming out in the evening to feed.   They are generally peaceful but can hold their own with other aggressive species.  Yo-Yo Loaches need a tank of at least 30 gallons with a sandy or extremely fine substrate, some plants, smooth river rocks, and driftwood for them to hide among, and plenty of swimming space.

Because they prefer subdued lighting, some floating plants can be added to the tank to diffuse the lighting and for cover.  These botias are excellent diggers and because of their delicate barbels, should definitely have a sandy substrate in their tank.   Because these loaches do jump at times, a tightly fitting cover is also essential.

The Yo-Yo Loach does best in well oxygenated water with some degree of current.   They are intolerant to the accumulation of organic wastes and require spotless water conditions to thrive, so a quality canister filter is recommended for this species.   For this reason, they should only be introduced into stable, biologically mature aquariums.    Weekly 30% to 50% water changes are recommended.

Although mature females regularly fill up with spawn, no successful spawning of the Yo-Yo Loach has been recorded in an aquarium environment.

In their natural environment, Yo-Yo Loaches  are chiefly carnivorous but will eat vegetative matter when available.   Their natural diet consists of insects, worms, aquatic mollusks, and other invertebrates.

In an aquarium environment, they are not fussy eaters and will eagerly accept a quality flake or pellet food, live or frozen bloodworms, tubifex, brine shrimp, and occasional offerings of fresh fruit and vegetables like melons, cucumber, blanched spinach, etc.   Chopped earthworms can be offered as a “treat” but only sparingly.   This species will also rid your tank of unwanted pond snails which they relish with gusto.

The Yoyo Loach or Pakistani Loach is usually available to tropical fish keeping enthusiasts online and in pet stores when they are 1 1/2″ to 3″ in length at a moderate cost.

Yo-Yo Loach (Botia almorhae)

Minimum Tank Size: 30 gallons
Care Level: Moderate
Temperament: Peaceful
Aquarium Hardiness: Moderately Hardy
Water Conditions: 75.0 – 86.0° F, 3 – 10 dGH, pH 6.5-7.5
Max Size: 6.1″
Color Form: Silver, Black
Diet: Omnivore
Compatibility: Good community tank fish
Origin: India, Pakistan
Family: Cobitidae
Lifespan: 8 – 12 years
Aquarist Experience Level:  Intermediate

Three spot gourami (Trichopodus trichopterus) are commonly found throughout Southeast Asia and are also known to tropical fish keeping enthusiasts as Blue Gourami.

Their range extends from Yunnan China through Laos, Cambodia, Malaysia, Myanmar, Singapore, Vietnam, Thailand, Java, Borneo and Sumatra, and they have been introduced into Trinidad, Sulawesi, and the Philippines.

Three Spot Gourami thrive in standing or very slow moving swamps, marshes, canals and flooded wetlands throughout their range where they feed on crustaceans, insect larvae, and zooplankton.

Blue Gourami (Trichogaster trichopterus) female

Three Spot Gourami or Blue Gourami, actually have only two dark blue to black spots over their silver blue bodies; one in the center of the body, and a second spot at the beginning of the caudal fin.   The third “spot” (that gives them their name) is actually their eye.

The body colors of these fish can change considerably depending on their mood and during spawning. Males have long pointed dorsal fins and a pointed anal fin.   In females, the anal fin is shorter and rounded, however some females have dorsal fins as long as a male.

Like others of their kind, Three Spot Gourami have a labyrinth organ that allows them to breathe atmospheric air to survive in stagnant waters with low oxygen content.  In an aquarium environment, they should always have access to the surface of the aquarium.

Three Spot Gourami are a peaceful, hardy species that can be housed with a variety other peaceful, similarly sized species.  They are somewhat territorial and can be aggressive with others of their species, especially during breeding.  The are known to be fin nippers when housed with species that have long, brightly colored flowing fins like male bettas, fancy male guppies, and goldfish.  Around more aggressive species, they tend to become much more timid.

Three Spot Gourami are best kept in a densely planted tank of at least 20 gallons with a sandy or fine gravel substrate, some rock work and driftwood for them to hide among, and plenty of swimming space.
Though they are tolerant of wide range of water parameters, they still require adequate filtration.

Three Spot Gourami are easy to breed.  The males build a bubble nest and when they are ready to breed will entice the female to spawn by repeatedly swimming back and forth under the nest with their tail raised and fins flared.  The male will wrap himself around the female and fertilize up to 800 eggs during a spawning.   After spawning is completed, it is generally recommended that the female be removed from the spawning tank.   The male will guard the bubble nest and usually shows aggression towards the female after spawning.  When the eggs hatch, the male will continue to guard the fry however, the male should be removed when the fry become free swimming and have absorbed their egg sacs.

After the fry are mobile, a tight fitting cover should be placed over the breeding tank to create and maintain the hot, humid environment needed for the labryinth organs to develop in the young gourami. Frequent water changes should be maintained during this stage as infusoria or baby brine shrimp is fed to the young.

Three Spot Gourami are omnivores and require meaty and algae based foods.   Live, frozen or freeze dried tubifex, bloodworms, brine shrimp and a quality omnivore flake food will provide these fish with all the nutrition they need.

Three Spot, or Blue Gourami are readily available to tropical fish keeping enthusiasts when they are 1 1/2″ to 2″ in size at reasonable prices.

Blue Gourami (Trichogaster trichopterus) Male

Minimum Tank Size: 20 gallons
Care Level: Easy
Temperament: Peaceful to Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-82° F, KH 4-18, pH 6.0-8.8
Max Size: 6″
Color Form: Blue, Silver
Diet: Omnivore
Compatibility: Good community tank fish
Origin: Southeast Asia, Malaysia, China
Family: Belontiidae
Lifespan: 5-8 years
Aquarist Experience Level: Easy

Giant Red Tail Gourami (Osphronemus laticlavius) are also known to tropical fish keeping enthusiasts as Giant Red Finned Gourami, Red Flag Giant Gourami, Giant Red Fin Goramy, and Red Tail Gourami and are found in Indonesia and Malaysia.

The four recognized species in the Osphronemus genus that are commonly referred to as giant gouramis are listed below along with their maximum lengths:

• Giant Gourami (Osphronemus gouramy) 28″ max
• Giant Red Tail Gourami (Osphronemus laticlavius) 20″ max
• Elephant Ear Gourami (Osphronemus exodon) 24″ max
• Kaloi Sarawak, Giant Gourami (Osphronemus septemfasciatus) 20″ max

Giant Red Tail Gourami are rare in the aquarium hobby and have only been known to science since the early 1990s.

Like Giant Gourami, Osphronemus laticlavius are found in the heavily vegetated stagnant waters of swamps, marshlands, and sluggish moving canals.  They are also found in slow moving rivers, lakes, and flooded forests during the rainy seasons and like other gourami, they posses a special labyrinth organ that enables them to survive in oxygen depleted waters.

Young Giant Red Tail Gourami (Osphronemus laticlavius)

Giant Red Tail Gourami have a laterally compressed, deep, oval shaped body, and a blunt head.  Juveniles have a steely blue gray to black body color that develops beautiful blue green highlights as the fish mature.  Adults have a blue green to almost black body color and fins that are trimmed in bright red, with filamentous extensions and a “nuchal” hump on their forehead.  The females usually have thicker lips.

Giant Red Tail Gourami make great pets.  Like Giant Gourami, they are able to recognize their owners and over time can develop real personalities.

Giant Red Tail Gourami are generally peaceful, but there can be exceptions to this rule, especially when they are housed in a small aquarium.  In rare instances a large male will become territorial and attack other fish, but in a properly sized tank, they are generally a good community fish with other larger species like knife fish, large catfish and loricariid.  When juveniles have been raised together with smaller barbs, tetras, danios, etc. they don’t consider their tankmates dinner and usually ignore them.  However, as they grow into adults, they “own” the tank and any new additions, regardless of size, will likely be killed.

Giant Red Tail Gourami should be housed in at least a 180 gallon or larger aquarium with a dark gravel or coarse sand substrate, some large rocks

Giant Red Tail Gourami (Osphronemus laticlavius) Juvenile

and pieces of driftwood for them to hide among, some floating plants, and plenty of free swimming space.   This species is a voracious herbivore so it is not advisable to plant slow growing aquatic vegetation in their tank.  Despite the fact that they can breathe atmospheric air and can tolerate a variety of water parameters, they need a good filtration system, some water movement, and clean water to thrive.  The use of a  canister filter and weekly 20-30% water changes are highly recommended.

In their natural habitat, male Giant Red Tail Gourami build ball shaped bubble nests approximately 16″ W. by 12″ D. out of bits of vegetable matter from 6″ to10″ below the surface of the water, and anchor it to the reeds or to subsurface grass.   The male takes about a week to 10 days to construct the nest (usually during April and May) at which time the spawning takes place.

Between 1,500 and 3,000 eggs are fertilized and released into the nest.  Both the eggs and the fry (when hatched) are lighter than water and will float to the top of the bubble nest.   The male will gather them into his mouth and place them into the nest where they are guarded until they hatch.   In approximately 40 hours the eggs hatch, and 15 days later the fry will be free swimming.

Breeding Giant Red Tail Gourami in an aquarium environment has not yet been reported, however, they probably breed in a similar fashion to
their cousin the Giant Gourami (Osphronemus goramy).   The fish are sexually mature at about 6 months of age or at a size of 4″ to 5″, however they still require a large breeding tank.  The male builds a large bubble nest with grasses, roots, small twigs, and floating plants and anchors it below the surface. The actual spawning occurs in the vicinity of the nest where the eggs are placed and tended to by the male until they hatch. The male then chases away the female and in 24 to 36 hours the eggs hatch. In 3 to 5 days the fry are free swimming and able to eat on their own however, the male will continue to guard the fry for several weeks unless removed from the tank. The fry can be fed crushed omnivore flake food
or newly hatched baby brine shrimp.

Giant Red Tail Gourami are opportunistic feeders and in their natural habitat will consume copious amounts of vegetable and animal matter.   Their natural diet consists of aquatic weedy vegetation, small fish, frogs, earthworms, crustaceans, and sometimes even carrion.

In an aquarium environment, they should be fed a balanced diet heavy on vegetable matter.

Besides omnivore flakes and pellets, they will eagerly accept live, frozen or freeze dried brine shrimp, worms, fish, bloodworms, algae wafers, lettuce, boiled potatoes, peas, cooked foods, etc.   Beef heart and meat from mammals should be only fed sparingly.   They are not picky eaters and will eat almost any aquarium food if trained to do so as juveniles.   Feed them once or twice daily.

Although the demand from tropical fish keeping enthusiasts for this species is high and the fish are quite pricey, Giant Red Tail Gourami are only occasionally available for purchase online.

Adult Giant Red Tail Gourami (Osphronemus laticlavius)

Minimum Tank Size: 180 gallons
Care Level: Moderate
Temperament: Relatively Peaceful
Aquarium Hardiness: Very Hardy
Water Conditions: 68-86°F, 5-25°H, pH 6.5-8.0
Max Size: 20″
Color Form: Blue, Gray, Red
Diet: Omnivore/Primarily Herbivore
Compatibility: Large Community Tanks
Origin: Indonesia, Malaysia
Family: Osphronemidae
Lifespan: 20+ years
Aquarist Experience Level: Intermediate

Giant Gourami (Osphronemus goramy) are native to Southeast Asia and are found throughout Borneo, Java, Sumatra, Thailand, Indo-china and the Malay Peninsula.   A recently described species called the Giant Red Tail Gourami (Osphronemus laticlavius) is slightly smaller and can be distinguished from Osphronemus goramy by its red fins.  Although this species is considered rare to tropical fish keeping enthusiasts, it’s care is identical to Osphronemus goramy.

Giant Gourami (Osphronemus goramy) are found in stagnant, slow moving waters of swamps, lakes, and large rivers in fresh and occasionally brackish water conditions.  Like other Anabantid, they have a well developed labyrinth organ that allows them to breathe moist atmospheric air and survive out of water, or in oxygen deficient conditions for extended periods.  In their natural habitat they can grow to over 28″ long, but in an aquarium environment they seldom exceed 18″ in length.

Partly because of their size, Giant Gourami are an important food source in many parts of their range.  They are commonly salted and dried in India and are popular in Malaysian, Indonesian, and even Sundanese cuisine.

Juvenile Giant Gourami (Osphronemus goramy)

Although they grow much larger than most gouramis, Giant Gourami are kept by many tropical fish keeping enthusiasts as juveniles when they are 2″ to 3″ long.

At this stage, they have a pronounced “beak” and have a pale to golden yellow body color, with silvery, pale blue vertical stripes running along the body.

The anal fins are large and rounded, and they have the distinctive elongated pelvic fins typical of gourami.  The body is very narrow in width, and the dorsal and anal fins in males end in a pronounced point. Females have thicker lips than males.

These fish grow rapidly when provided with sufficient space and plenty of food, and within four or five years they can grow as long as 18″ to 20″ in length.   As they mature, between 3 to 4 years of age, Giant Gourami will lose their juvenile coloring and turn a dark gray to almost black color.   They will begin to develop a rounded face and a large “nuchal hump” on the head, just above their eyes.  During spawning, the body colors of the fish turn almost black.

Giant Gourami (Osphronemus goramy)

Giant Gourami are a relatively peaceful, long lived, extremely hardy, intelligent fish that make great “pets” for their owners.  They develop real personalities and change their body color according to their moods.  They recognize their owners and will visually respond to them with something akin to affection.

Giant Gourami are best housed in a 180 gallon or larger aquarium with a gravel or coarse sand substrate, plenty of hiding places in the form of large rocks or large pieces of  driftwood, and because they are a “messy” fish, a powerful filtration system.   These fish are extremely efficient herbivores, therefore floating plants are much more preferable than having planted aquatic vegetation in the tank.

Giant Gourami are known to eat smaller fish, but they are usually peaceful with other large fish provided enough space if provided in the aquarium. As juveniles they can be housed with Angelfish, Bala Sharks, Bettas, Clown Loaches, Danios, Rainbowfish, Neons and most catfish.

As adults they may become aggressive, but this is usually due to being kept in an aquarium that is too small.  In a large aquarium with plenty of space, these fish will usually get along well with the above species as well as knifefish, large catfish, and loricariids as long as they are introduced at the same time.  Avoid adding new specimens to an established tank regardless of their size.

Giant Gourami are relatively easy to breed, but a huge tank is required to breed fully grown adults.  Fortunately Giant Gourami are sexually mature at around 6 months, so it’s much more realistic to breed younger fish in lieu of adults.

Set up a large breeding tank with lots of floating plants and weeds or twigs so the male can build a large bubble nest using the vegetation.  Spawning will occur close to the nest and the male will catch the eggs as they are fertilized an include them into the nest.  After spawning is completed, the female should be removed from the breeding tank.  The male tends to the nest until the eggs hatch, usually within 24 to 36 hours.  The fry become free swimming 3 to 5 days later and the male will continue to guard the fry for several weeks.  Most breeders elect to remove the male from the breeding tank once the fry are free swimming.  They can be fed newly hatched baby brine shrimp or powered flake food almost from the first day.

Although Osphronemus goramy are omnivorous, they are voracious herbivores.  In the wild they eat all types of vegetable matter and are even used for weed control in many areas, but they will also eat worms, amphibians, and sometimes even dead animals.  In an aquarium environment, they are not fussy eaters but should be given an algae based flake food along with a varied diet of live, frozen or freeze dried bloodworms, tubifex, brine shrimp, worms, and as adults; large pellets, legumes, fruits, and partially or fully cooked vegetables.

Giant Gourami are available to tropical fish keeping enthusiasts online and from specialty fish keeping shops as juveniles when they are 2″ to 3″ in length.

Giant Gourami (Osphronemus goramy)

Minimum Tank Size: 180 gallons
Care Level: Easy
Temperament: Relatively Peaceful
Aquarium Hardiness: Very Hardy
Water Conditions: 68-86°F, 5-25°H, pH 6.5-8.0
Max Size: 28″
Color Form: Yellow, Gray, White
Diet: Omnivore/Primarily Herbivore
Compatibility: Large Community Tanks
Origin: Southeast Asia
Family: Osphronemidae
Lifespan: 20+ years
Aquarist Experience Level: Intermediate

Giant Chocolate Gourami (Sphaerichthys acrostoma) are known to tropical fish keeping enthusiasts as the Sharp Nosed Gourami, Moonlight Chocolate Gourami, Black Lined Chocolate Gourami, and Black Tailed Chocolate Gourami.   They are found only within the Indonesian parts of the island of Borneo and appear to be well distributed within the Mentaya River drainage system near the town of Sampit and further south.

Giant Chocolate Gourami grow to almost 4″ in length are are primarily found in peat swamps and forested blackwater streams littered with rotting leaves and fallen tree branches that are typically stained a dark brown to almost black color by the humic acids and other chemicals released from decaying organic matter.

The decomposition results in a negligible dissolved mineral content in the water and a pH value as low as 3.0 or 4.0.   The dense jungle growth and the rainforest canopy allows very little light to penetrate the surface of the water, letting only low light loving plants like Utricularia, Cryptocoryne, Blyxa, Barclaya, Eleocharis, Utricularia, and Lymnophila to grow.

Giant Chocolate Gourami (Sphaerichthys acrostoma) Adult Male

Giant Chocolate Gourami have a high, flattened, moderately elongated body with a long dorsal and anal fin, and low filamentous pelvic fins.   The overall body color is bronze with slightly networked scales, dark fins, and a light throat.   There are two black cherry colored lines that extend from the tip of the snout through the eye, to the end of the gill cover.

When excited, males show a bright lateral band that extends from the caudal fin to the middle of the body.  Females lack this band but have a series of dark vertical lines on the lower front of the body in the abdominal region and along the base of the anal fin.

Females have a uniformly brown body with some red pigmentation in the throat and the unpaired fins.   The

females also have an overall more acuminate head shape than males and a uniformly straight lower jaw profile.

Like others in the suborder Anabantoidei, Sphaerichthys acrostoma possess a labyrinth organ that allows them to breathe atmospheric air and survive in oxygen depleted water conditions.

Some species collected along with Giant Chocolate Gourami in the tannin stained jungle streams included Betta foerschi, Parosphromenus parvulus, Hemirhamphodon chrysopunctatus, Pectenocypris korthausae, Puntius foerschi, and Osteochilus pentalineatus.

Giant Chocolate Gourami do best in a single species tank with at least 6 or 8 of their own kind or they can be housed with other peaceful pelagic cyprinids like the Glowlight Rasbora (Trigonostigma hengeli), other smaller Rasbora species, loaches like the Kuhli Loach (Pangio semicincta ) or Kottelatlimia spp. or any of the above species.

Giant Chocolate Gourami should be housed in a densely planted 30 gallon or larger aquarium, with a sandy or fine gravel substrate covered with dried leaf litter, lots of driftwood roots, wood bark, and branches formed into small caves.    Use low light loving plants like Microsorum, Taxiphyllum, Cryptocoryne, and Anubias to decorate and create hiding places for the fish.  Provided adequate cover and structure is available, this species is not fussy about their decor.  Some tropical fish keeping enthusiasts place ceramic flowerpots, pieces of PVC pipe, and other artificial materials into their tanks for cover, but a more aesthetically pleasing environment that mimics their natural habitat is preferable.

Beach, Oak, or Ketapang Indian Almond Leaves should be placed on the bottom of the tank to replicate the blackwater conditions these fish are found in, and to keep the pH in the water low.   The microbe colonies that are produced as the leaves decompose in the tank become a secondary food source for the fish and the fry, and although the chemicals and tannins released cause the water to turn a dark brown color, they are medicinal and prevent fungal infections in the fish.   The leaves can either be removed and replaced every few weeks, or left in the tank to fully decompose.

To keep Giant Chocolate Gourami healthy, diffused lighting, soft water, and a low pH level is critical.   Because this species is found in still, or sluggish moving streams under jungle canopies where very little light penetrates the water column; introduce a few patches of floating plants into the aquarium to diffuse the lighting.   They are a shy, timid, slow moving species intolerant of changing water conditions, so when performing a water change to their tank, only change out about 10 to 15% weekly or when necessary.   This species is best kept in a mature, aged aquarium with little or no current in the tank.

Giant Chocolate Gourami are paternal mouthbrooders that can be bred either in a group or in pairs.  Breeding can be expedited by setting up a breeding tank with a pH below 5.0 and a dH below 2.    Breeding will usually take place if the fish are well conditioned and the amount of organic waste in the tank is low.   The female or alpha female (if in a group) will normally initiate courtship.

Giant Chocolate Gourami (Sphaerichthys acrostoma) Male

The male will display a lateral stripe that extends from the base of the caudal fin to about mid-body.

Females lack this stripe but possess a series of darkened scale rows in the lower anterior portion of the body and along the base of the anal fin, and a red pigmented area on the throat and in the unpaired fins that increase in intensity.

Giant Chocolate Gourami (Sphaerichthys acrostoma) Female

The pair remains mostly upright during the spawning process which can take several hours to complete.   During spawning, both parents will defend the surrounding territory, and when the distinctly pear shaped eggs are laid and fertilized on the substrate, the male collects them in his mouth and retires to a quiet area in the tank where he will not eat until the eggs hatch and the fry are fully formed.   Usually within 7 to 20 days, the male will release anywhere from 20 to 60 fully formed free swimming juveniles into the tank.

At this point the fry can be removed to a rearing tank with the exact same water parameters, or the parents can be removed to minimize predation.   A tightly fitting cover must be placed on the rearing tank to create the humid air conditions needed for the proper development of the labyrinth organs of the fry.

When released from the mouth of the male, the fry are large enough to immediately accept or freshly hatched baby brine shrimp.  During the rearing process, about 10% of the water in the tank should be changed daily to promote growth and maintain water quality.

In their natural habitat, Giant Chocolate Gourami feed on small aquatic crustaceans, insect larvae, worms, and zooplankton among the leaves.   Wild caught specimens will usually need a steady diet of live or frozen mosquito larvae, brine shrimp, Daphnia, grindal worms, , or bloodworms.    They may accept freeze dried bloodworms and even a quality carnivore flake food if the fish have been captive bred, but this species is a picky eater so be prepared to stock up on live and frozen foods if you intend to keep them.

Giant Chocolate Gourami are seldom available to tropical fish keeping enthusiasts and are often sold as Sharp Nose Gourami, Moonlight Chocolate Gourami, Black Lined Chocolate Gourami, and Black Tailed Chocolate Gourami.

Giant Chocolate Gourami (Sphaerichthys acrostoma)

Minimum Tank Size: 20 gallons
Care Level: Difficult
Temperament: Shy, Peaceful
Aquarium Hardiness: Delicate
Water Conditions: 74-86°F, 0-54 ppm, pH 3.5-6.5
Max Size: 4″
Color Form: Brown, White
Diet: Carnivore
Compatibility: Biotope setup
Origin: Mentaya River drainage Borneo, Indonesia
Family: Osphronemidae
Lifespan: 5-8 years Aquarist
Experience Level: Advanced

Crossband Chocolate Gourami (Sphaerichthys selatanensis) also known as the Cherry Chocolate Gourami, are found close to the the city of Banjarmasin in South Kalimantan, Borneo, Indonesia. They appear to be well distributed in southern Borneo and have also been collected close to the settlement of Sampit, which is several hundred kilometers east in Central Kalimantan province.

Similarly patterned Crossband Chocolate Gourami have been recorded on Belitung Island, Bangka Belitung Islands province, Indonesia which lies just off the eastern coast of Sumatra.  These specimens have a more reddish color than the Borneo forms and are the first ever, other than Sphaerichthys osphromenoides, recorded outside of Borneo.

Like other Anabantoidei, Crossband Chocolate Gourami possess a labyrinth organ that allows them to breathe atmospheric air to survive in oxygen deficient conditions that would kill many other species.

Crossband Chocolate Gourami are found in blackwater peat swamps, the adjacent streams of their range, and sometimes in clear water areas that are tannin stained a dark brown color by the decomposition of leaves, brush, and other organic materials.   The humic acids and other chemicals released by decomposition is beneficial to the fish and causes the water to turn a dark brown color.  This decomposition also causes the pH of the water to drop into the 3.0 or 4.0 range and results in a negligible dissolved mineral content (very soft water).

Because their normal habitat is in very slow moving waters littered with fallen tree branches, brush, and rotting leaves and under the dense jungle rain forest canopy where very little light is present, the fish should never be housed in a brightly lit tank or a tank with a strong current.

The clearer water habitats where Crossband Chocolate Gourami are sometimes found are similar in terms of water chemistry, but in most cases cause profuse growths of aquatic vegetation. Lymnophila, Utricularia, Cryptocoryne, Blyxa, Barclaya, and Eleocharis are representative genera of these areas and can be used in a low light aquarium environment.

Crossband Chocolate Gourami (Sphaerichthys selatanensis)

Like Chocolate Gourami (Sphaerichthys osphromenoides), male Crossband Chocolate Gourami (Sphaerichthys selatanensis) are colored brown with white vertical stripes, however, Sphaerichthys selatanensis have an additional light, vertically orientated bar on each flank originating just ahead of the dorsal fin and terminating just after the ventral fins.

In Sphaerichthys osphronemoides, this extra bar is absent or reduced to a small spot just behind the dorsal fin.  Females are generally more colorful than the males and adult males have a uniformly straight lower jaw profile and a more acuminate head shape than females.

Samurai Gourami (Sphaerichthys vaillanti) and Giant Chocolate Gourami (Sphaerichthys acrostoma) can be distinguished by their more elongate head and body profile, their reverse sexual dimorphism (females are more colorful), and the fact that they are paternal mouth brooders.

Crossband Chocolate Gourami are a shy, timid, and very slow moving species that should be housed in a biotope system with at least 6 to 8 of their own kind.

In the tannin stained jungle streams where they are found, they have been collected along with Betta foerschi, Deissner’s Liquorice Gourami (Parosphromenus parvulus), HalfBeaks (Hemirhamphodon chrysopunctatus), Pectenocypris korthausae, Foersch’s Fire Barb (Puntius foerschi), and Borneo bonylipped barb (Osteochilus pentalineatus).

Crossband Chocolate Gourami should be housed in a densely planted 20 gallon or larger aquarium, with a sandy or fine gravel substrate covered with dried leaf litter, lots of driftwood roots, wood bark, and branches formed into small caves for hiding places.

Oak, Beach, or Ketapang Indian Almond Leaves should be placed on the bottom of the tank to replicate the blackwater conditions these fish are found in, and to keep the pH in the water low.   As the leaves decompose in the tank, the microbe colonies that result provide a secondary food source for the fish and fry.  The tannins and chemicals released into the water are known to be medicinal, and will prevent fungal infections.  The leaves can either be removed and replaced every few weeks or so, or left in the tank to fully decompose.

Some tropical fish keeping enthusiasts place lengths of PVC plastic pipe or ceramic flowerpots into the tank for hiding places, but aesthetically, bogwood or driftwood roots are preferred.  Use low light loving plants like Microsorum, Taxiphyllum, Cryptocoryne, and Anubias to decorate and create hiding places for the fish.

To keep Crossband Chocolate Gourami healthy, diffused lighting, soft water, and a low pH level is critical.  This species lives in still, or very slow moving streams under the jungle canopy where very little light penetrates the water column.  Some floating plants in the aquarium do diffuse the light and very little current in the tank will mimic these conditions.

Avoid making large water changes that drastically change the chemistry of the aquarium. Performing a 10 to 15% water change every week, or every other week is more than adequate.  This species should only be kept in an aged aquarium.

Crossband Chocolate Gourami are maternal mouth brooders where the female broods the eggs.   This is unique in that the only other anabantoid species where the female broods the eggs is the Chocolate Gourami (Sphaerichthys osphromenoides osphromenoides).

Sphaerichthys selatanensis can be bred in a group or as a single pair, as long as the water quality and their conditioning diet is properly maintained.

Use a separate breeding tank with Peat blackwater extract and maintain the pH level at pH 6.2.   Lowering the water level and slowly raising the water temperature in the tank over a two by 2°, and then slowly adding some cooler water to the tank will usually initiate breeding activity.

The male will usually initiate courtship which can be recognized when the male turns a dark, almost gray pattern.  The colors in the female will intensify to a deep chocolate brown, with the light white vertical bars turning into an almost gold color.

The pair remains upright during the spawning, which may take several hours to accomplish.  When the eggs are laid and fertilized on the substrate, the female then collects them into her mouth.  The eggs are unique in that they are pear shaped and have a series of spiraling ridges on their outer surface.  Both parents will guard their territory until spawning is completed.

After the eggs are gathered by the female, she will find a quiet area in the tank where she will remain until the eggs hatch and the fry are fully formed.  This usually takes from 7 to 20 days, during which time the female does not eat.  After the fry are fully formed, the female will release anywhere from 10 to 40 free swimming fry from her mouth.

At this point the parents should be removed from the breeding tank and a tight fitting cover should be placed over the tank to create the humid air conditions required for the proper development of the labyrinth organ of the fry.  The fry are large enough to immediately accept microworms or freshly hatched baby brine shrimp.

During the rearing process, about 10% of the water in the tank should be changed daily to promote growth and maintain water quality.

In their natural habitat, Crossband Chocolate Gourami feed on small aquatic crustaceans, insect larvae, worms, and zooplankton among the leaves.  Wild caught specimens require a steady diet of live or frozen mosquito larvae, brine shrimp, Daphnia, grindal worms, , or bloodworms.  They may accept freeze dried bloodworms and even a quality carnivore flake food if the fish have been captive bred, but this species is difficult to feed, so be prepared to stock up on live and frozen foods if you intend to keep them.

Crossband Chocolate Gourami are only occasionally available to tropical fish keeping enthusiasts and are often sold as Cherry Chocolate Gourami.

Crossband Chocolate Gourami (Sphaerichthys selatanensis)

Minimum Tank Size: 20 gallons
Care Level: Difficult
Temperament: Shy, Peaceful
Aquarium Hardiness: Moderately Hardy
Water Conditions: 74-86°F, 0-54 ppm, pH 4.0-6.5
Max Size: 1.8″
Color Form: Brown, White
Diet: Carnivore
Compatibility: Biotope setup
Origin: Southern Borneo, Indonesia
Family: Osphronemidae
Lifespan: 5-8 years
Aquarist Experience Level: Intermediate or better

Chocolate Gourami (Sphaerichthys osphromenoides osphromenoides) are found in the Malay Peninsula, Sumatra, and Borneo throughout the Malaysian state of Sarawak and the Indonesian province of West Kalimantan (Kalimantan Barat).

Like other Anabantoidei, they possess a labyrinth organ that allows them to breathe atmospheric air to survive in oxygen depleted conditions that would kill most other species.

Chocolate Gourami are mainly found in the blackwater peat swamps and adjacent streams of their range, and sometimes in clear water areas that are tannin stained a dark brown color by the decomposition of leaves, brush, and other organic materials.  The humic acids and other chemicals released as decomposition occurs is beneficial to the fish and causes the water to turn a dark brown, to almost black color.  The decomposition also causes the pH of the water to drop into the 3.0 or 4.0 range and results in a negligible dissolved mineral content.

Because their normal habitat is found under the dense jungle rain forest canopy in slow moving waters littered with fallen tree branches, brush, and rotting leaves where very little light is present, the fish should never be kept in a brightly lit tank with a strong current.

The clearer water habitats where Chocolate Gourami are sometimes found are similar in terms of water chemistry, but in many cases cause aquatic vegetation to grow profusely.   Utricularia, Cryptocoryne, Blyxa, Barclaya, Eleocharis, and Lymnophila are representative genera of these areas.

Chocolate Gourami (Sphaerichthys osphromenoides osphromenoides)

Male Chocolate Gourami are colored a brown with white vertical stripes.

The males have a yellow border along the edge of their unpaired fins and in some populations, the fins of the male are more blueish or reddish.

Some male populations have more deeply forked caudal fins and more extended dorsal and anal fins.   Adult males have a straighter lower jaw profile than females and a more acuminate head shape.   The lower jaw is also slightly rounded because of the distensible skin that expands during mouthbrooding.

Chocolate Gourami (Sphaerichthys osphromenoides osphromenoides)

Chocolate Gourami are a shy, very timid, and slow moving species that should be housed in a biotope system with at least 6 to 8 of their own kind.

They have been collected along with Glowlight Rasboras (Trigonopoma pauciperforatum), Giant Pikehead (Luciocephalus pulcher), Nandus nebulosus, Brilliant Rasboras (Rasbora einthovenii), Dwarf Rasbora (Boraras maculatus), Java Combtail (Belontia hasselti), Betta waseri, Betta Tussyae, Crescent Betta (B. imbellis), and the Striped Glass Catfish (Kryptopterus macrocephalus).

All are slow moving, blackwater species that can be considered candidates for a biotope blackwater “community” aquarium.

Sphaerichthys osphromenoides osphromenoides can be housed in a densely planted 20 gallon or larger aquarium, with a sandy or fine gravel substrate covered with dried leaf litter, and lots of driftwood roots or branches for cover, in the form of small caves.  Oak, Beach, or Ketapang Indian Almond Leaves are necessary to replicate the blackwater conditions these fish are found in and to keep the pH in the water low.   As they decompose in the tank, the microbe colonies provide a secondary food source for the fish and fry.  The tannins and chemicals released are known to be medicinal and to prevent fungal infections.  The leaves or leaf litter can be removed and replaced every few weeks or so, or left in the tank to fully decompose.

Some tropical fish keeping enthusiasts place lengths of PVC plastic pipe or ceramic flowerpots in the tank for hiding places, but aesthetically, bogwood or driftwood roots are preferred.  Low light loving plants such as Microsorum, Taxiphyllum, Cryptocoryne, and Anubias are recommended for the tank.

To keep Chocolate Gourami healthy, soft water and a low pH is critical.   And, because they live in still, slow water environments under the jungle canopy, there should be very low lighting and very little or no current in the aquarium.    Adding some floating plants to the tank is an effective method for diffusing the light.

Avoid large water changes that can drastically change the chemistry of the system.   A 10 to 15% water change every week is more than adequate.  This species should only be kept in an aged aquarium.

Like the Samurai Gourami (Sphaerichthys vaillanti), Chocolate Gourami (Sphaerichthys osphromenoides osphromenoides) are mouth brooders.

However, unlike Samuari Gourami, Chocolate Gourami are maternal mouthbrooders where the female broods the eggs.   This is unique in that the only other anabantoid species where the female broods the eggs is the Crossband Chocolate Gourami (Sphaerichthys selatanensis).

Chocolate Gourami can be bred in a group or as a single pair as long as the water quality and their conditioning diet is maintained.

To initiate breeding, use peat extract and a pH of 6.2 in a breeding tank.   Lower the water level and raise the water temperature gradually over a two day period by 2°  and then slowly add some cooler water to the tank.

The male will normally imitates courtship which can be recognized when the male takes on a dark almost gray patterning.  The females color will intensify into a deep chocolate brown, with the light vertical bars turning into an almost golden color.

The pair remains almost upright during the spawning, which may take several hours to accomplish.  The eggs are laid and fertilized on the substrate where the female then collects them into her mouth.  Both the male and female will guard their territory until spawning is completed.  The female will then go to a quiet area in the tank where she will remain until the eggs hatch and the fry are fully formed.  This usually takes from 7 to 20 days, during which time the female does not eat.  After the fry are fully formed, the female releases from 10 to 40 free swimming fry from her mouth.

At this point the female should be removed from the breeding tank.  A tight fitting cover should be placed over the tank to create the humid air required for the proper development of the labyrinth organ of the fry.   They fry are large enough to immediately accept or freshly hatched baby brine shrimp.

During rearing, about 10% of the water in the tank should be changed daily to promote growth and maintain the water quality.

In their natural environment, Chocolate Gourami feed on small aquatic crustaceans, insect larvae, worms and zooplankton.  Most wild caught specimens require a steady diet of live or frozen mosquito larvae, brine shrimp, Daphnia, grindal worms , and bloodworms.   They may accept freeze dried bloodworms and even a quality carnivore flake food if the fish have been bred in captivity, but be prepared to stock up on live and frozen foods if you plan to keep this species.

Chocolate Gourami are not often available to tropical fish keeping enthusiasts.  The best way to obtain specimens is to special order through specialty dealers or purchase them online.  They are usually quite costly.

Chocolate Gourami (Sphaerichthys osphromenoides osphromenoides)

 
Minimum Tank Size: 20 gallons
Care Level: Difficult
Temperament: Shy, Peaceful
Aquarium Hardiness: Moderately Hardy
Water Conditions: 77-81°F, 1-4 dH , pH 6.0-7.0
Max Size: 2″
Color Form: Brown, White
Diet: Carnivore
Compatibility: Biotope setup
Origin: Asia; Sumatra, Borneo, Malay Peninsula
Family: Osphronemidae
Lifespan: 5-8 years
Aquarist Experience Level: Intermediate or better