Pearlscale Butterflyfish (Chaetodon xanthurus)

Pearlscale Butterflyfish (Chaetodon xanthurus) known to tropical fish keeping enthusiasts as Yellow Tailed Butterflyfish, Crosshatch Butterflyfish or Philippines Chevron Butterflyfish is central Indo-Pacific region from Indonesia and the Philippines north to the Ryukyu Islands.

Pearlscale Butterflyfish can be encountered alone, in pairs, and in small groups along drop offs in the clear, coastal outer reef slopes of their range, usually around areas colonized with rich growths of Acropora staghorn corals, at depths from 20 to over 160 feet where they feed on various algae, soft coral polyps, and small benthic invertebrates.

Pearlscale Butterflyfish (Chaetodon xanthurus)

The Pearlscale Butterflyfish has iridescent pearly white body scales edged with black, in a striking contrasting reticulated (net like) or crosshatched pattern. They have a white rimmed, black oval splotch on the forehead behind the eye, a black vertical line through the eye, a bright orange sickle shaped band over the anterior dorsal and anal fins that are highlighted with delicate white, black, and yellow edging, a translucent orange and white caudal fin, and bright yellow on the tips of the dorsal fin. There are no discernible differences between males and females.

They are often mistaken for Mertensii Butterflyfish (Chaetodon mertensii).

Although Pearlscale Butterflyfish can be housed in a mature reef tank with caution; they are best housed in a well established FOWLR aquarium of at least 100 gallon capacity with a fine crushed coral or sand substrate, mature live rock arranged into caves, crevices, and overhangs for them to graze on and hide among, and plenty of free swimming space. In mature aquariums containing plenty of live rock for the fish to browse on and forage among, they will normally thrive.

Like Chaetodon semilarvatus, Chaetodon xanthurus feed on several species of soft corals and small invertebrates, they are not considered reef safe, however, many tropical fish keeping enthusiasts with very large reef systems have successfully reported housing

Pearlscale Butterflyfish (Chaetodon xanthurus)

Chaetodon xanthurus with some of the more noxious, unpalatable soft corals. They may, or may not, exhibit curiosity and nip at coral polyps, particularly SPS corals.

Pearlscale Butterflyfish often become territorial towards similar looking, colored, or patterned butterfly species, especially when housed in smaller tanks, however; they can coexist when simultaneously introduced as juveniles into a large mature aquarium.

As a general rule it is never a good idea to mix butterflyfish species together, especially close relatives. A few compatible species include Banggai Cardinalfish (Pterapogon kauderni), Firefish Goby (Nemateleotris magnifica), Royal Gramma (Gramma loreto), Clownfish (Amphiprioninae), and Cleaner Shrimp (Lysmata amboinensis).

Pearlscale Butterflyfish tankmates in FOWLR systems should be the same size and peaceful in nature.   They will often refuse to eat or venture out of the protection of their live rock crannies when kept with more belligerent species. They will almost always acclimate well and thrive when kept in peaceful surroundings.

Like all butterflyfish, Chaetodon xanthurus require water quality that is thoroughly filtered and well oxygenated, along with moderate water flow.  An excellent filtration system, protein skimmer, and wave maker should be mandatory.

In the wild, Pearlscale Butterflyfish form distinct pairs and scatter their eggs in open water. They have not been bred in an aquarium environment.

In their natural habitat, Pearlscale Butterflyfish feed on algae, soft coral polyps, gorgonians, and small benthic invertebrates. In an aquarium environment, they should be fed a variety of live, frozen, or freeze dried foods that includes high quality marine flakes, omnivore pellets, spirulina, prepared foods containing algae, chopped krill, clams, or mussels, mysis shrimp, and vitamin enriched brine shrimp.
Feed small portions several times daily.

Pearlscale Butterflyfish (Chaetodon xanthurus) are readily available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at prices that vary according to size and area of collection.

Approximate purchase sizes: Small: 1″ to 2-1/4″, Medium: 2-1/4″ to 3-1/2″, Large: 3-1/2″ to 4-3/4″.

Currently prices for small specimens start at around $52.99 for small Fiji specimens, up to $104.99 for large specimens.

Pearlscale Butterflyfish (Chaetodon xanthurus)

Minimum Tank Size: 100 gallons
Aquarium Type: FOLR
Care Level: Easy to Moderate
Temperament: Peaceful
Aquarium Hardiness: Moderately Hardy
Water Conditions: 74-80° F, dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 5.9″
Color Form: White, Black, Orange, Yellow
Diet: Omnivore
Compatibility: Reef with Caution
Origin: Indo Pacific
Family: Chaetodontidae
Lifespan: Over 7 years
Aquarist Experience Level: Intermediate

Golden Semilarvatus Butterflyfish (Chaetodon semilarvatus)

Golden Semilarvatus Butterflyfish (Chaetodon semilarvatus) is known to tropical fish keeping enthusiasts by a variety of names including; Bluecheek Butterflyfish, Addis Butterflyfish, Masked Butterflyfish, Blue Cheeked Butterflyfish, Bluemask Butterflyfish, Coralfish, Golden Butterflyfish, Golden Masked Butterflyfish, Red-lined Butterflyfish, Red Sea Butterflyfish, Red Sea Golden Butterflyfish, Semilarvatus Butterfly, and Yellow Butterflyfish.

Found in the Northwestern Indian Ocean, their range extends into the Red Sea and the Gulf of Aden, as far east as the coast of Oman.

In their range, Golden Semilarvatus Butterflyfish are a common species that are encountered in pairs and small shoals among reefs rich in coral growth, at depths from the surface to over 65 feet where they can be seen feeding on benthic invertebrates and hard corals. They are occasionally seen hovering in a stationary position for long periods beneath ledges of plate corals of the genus Acroporak.

Golden Semilarvatus Butterflyfish (Chaetodon semilarvatus)

Golden Semilarvatus Butterflyfish have a bright yellow body striped with delicate thin red vertical lines and a bluish gray mask covering the eyes.   The dorsal, anal, pelvic and caudal fins are yellow.

Bluecheek Butterflyfish are best housed in a well established FOWLR aquarium of at least 125 gallon capacity with a fine crushed coral or sand substrate, mature live rock arranged into caves, crevices, and overhangs for them to graze on and hide among, and plenty of free swimming space. Because they eat soft corals and small polyp stony corals as well as ornamental shrimp, tube worms and anemones, they are not considered reef safe.

Golden Semilarvatus Butterflyfish are a peaceful species that can be housed alone, in pairs, or in groups with other peaceful fish of similar size and temperament in the same aquarium, however, they may become aggressive towards other Butterflies with a similar pattern or coloration when housed in smaller tanks.

Although the Golden Semilarvatus Butterflyfish is one of the few species to have long term mates, Chaetodon semilarvatus have not been reportedly bred in an aquarium environment. In the wild, pairs will normally spawn in the water column during the day. At night the eggs emerge into active larvae.

In their natural habitat Golden Semilarvatus Butterflyfish feed primarily on hard corals and benthic invertebrates. In an aquarium environment, they should be fed a variety of meaty foods like vitamin enriched brine shrimp, seaweed, nori, spirulina, marine algae, and prepared algae based foods.

Feeding small portions of high quality marine flakes, pellets, frozen foods, and live offerings of brine shrimp or mysis shrimp 2 to 3 or more times a day is recommended.

Golden Semilarvatus Butterflyfish (Chaetodon semilarvatus) are occasionally available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at prices that vary according to size and area of collection.

Approximate purchase sizes are for Small: 1″ to 2-1/4″; Medium: 2-1/4″ to 3-1/2″; Large: 3-1/2″ to 5″

Prices start at around $ 349.99 for small Red Sea specimens.

Minimum Tank Size: 125 gallons
Aquarium Type: FOLR
Care Level: Moderate
Temperament: Peaceful
Aquarium Hardiness: Hardy
Water Conditions: Temp 72-78° F, dKH 8 – 12°, pH 8.1-8.4, Salinity 1.022-1.025
Max size: 9″
Color Form: Black, Orange, Yellow
Diet: Omnivore
Compatibility: Not reef safe
Origin: Northwestern Indian Ocean
Family: Chaetodontidae
Lifespan: 5 – 7 years
Aquarist Experience Level: Intermediate

Wrought Iron Butterfly (Chaetodon daedalma)

Wrought Iron Butterflyfish (Chaetodon daedalmahe) known to tropical fish keeping enthusiasts as Black Silk Butterflyfish are found in the Northwest Pacific Ocean around central and southern Japan, primarily around the main islands of Japan south of Sagami Bay; notably Ryukyu, Bonin, and the Ogasawara and Izu Islands, where they are endemic.

Wrought Iron Butterflyfish are a sociable, nomadic species commonly found offshore around the islands of their range, alone, in pairs, and more often in small pods in the clear waters of the rocky, outer coral reefs of their range.

Wrought Iron Butterflyfish occasionally form up into very large schools called “wrought iron balls” as they graze on algae, zooplankton, fanworms, hydroids, gastropods, barnacles, tunicates and other benthic invertebrates over wide areas of the ocean floor, mostly at depths from 35 to over 90 ft.   Many researchers believe that the “wrought iron ball” formations are a defensive strategy.

Wrought Iron Butterfly (Chaetodon daedalma)

Wrought Iron Butterflyfish have a black body with yellowish white edged scales that give it a stunning metallic like cross hatched appearance.   The dorsal, anal, and caudal fins are edged in yellow.

Juveniles have a vertical, more white colored splotch on the sides behind the gills that disappear as they grow into adults.

Black Silk Butterflyfish are best housed in a well established FOWLR aquarium of at least 125 gallon capacity with a fine crushed coral or sand substrate, mature live rock arranged into caves, crevices, and overhangs for them to graze on and hide among, and plenty of free swimming space.

Because Wrought Iron Butterflyfish relish tubeworms and pick at Large polyp stone coral (LPS),  Small polyp stone coral (SPS), soft corals, Tridacna clams, and most crustaceans; they are not reef safe.

Wrought Iron Butterfly (Chaetodon daedalma)

Chaetodon daedalmahe can be housed alone, in pairs, or with groups of fish of similar size and temperament in the same aquarium without worry.  They are generally shy and peaceful but can become territorial if their aquarium is to small.

Wrought Iron Butterflyfish require a good filtration system, efficient protein skimming, a wave maker for water movement, and a chiller to maintain their cooler water conditions.

Chaetodon daedalmahe have not been reportedly bred in an aquarium environment. They are an oviparous species. Males and females form up into pairs for breeding.

In their natural habitat, Wrought Iron Butterflyfish graze on zooplankton, algae, fan worms, hydroids, gastropods, barnacles, tunicates and other benthic invertebrates in the water column and on the ocean floor. In an aquarium environment, they should be fed a varied diet of high quality omnivore pellets along with fresh or frozen meaty and algae based foods. Krill, mysis, artemia, Cyclops, spirulina, etc. should be fed multiple times daily.

Outside of the Japanese tropical fish keeping trade, Wrought Iron (Chaetodon daedalmahe) are rarely exported and seldom available to fish keeping enthusiasts in the United States. Their rarity, restricted distribution, and cooler water keeping requirements make them a valuable species that when exported and available for sale exceed $2500.00 USD.

Current prices for small size under 2″ specimens start at $5,999.99 USD; Medium 2″-3″ to XLarge 4″-5″ quarantined specimens sell from $7,499.99 to $9,999.99 USD.

Wrought Iron Butterfly (Chaetodon daedalma)

Minimum Tank Size: 125 gallons
Aquarium Type: FOLR
Care Level: Moderate
Temperament: Peaceful
Aquarium Hardiness: Hardy
Water Conditions: Temp 68-75F, dKH 8 – 12°, pH 7.8-8.5, Salinity 1.022-1.026
Max size: 6″
Color Form: Black, Blue, White
Diet: Omnivore
Compatibility: Not reef safe
Origin: Ryukyu, Bonin, Izu, Japan
Family: Chaetodontidae
Lifespan: Over 10 years
Aquarist Experience Level: Intermediate

Black Triggerfish (Melichthys niger)

Black Triggerfish (Melichthys niger) known to tropical fish keeping enthusiasts as Hawaiian Black Trigger, Black Durgon, Black Finned Triggerfish, or in Hawaiian, Humuhumu’ele’ele are found worldwide in Tropical Atlantic/Caribbean, Tropical Eastern Pacific, and Tropical Indo Pacific waters.

Its range extends from Hawaii, up through Polynesia, westward to the East Indies and across the Indian Ocean. The black triggerfish is also located around the southern coast of Africa.

Black Triggerfish are uncommon in most areas of their range, but appear abundantly in small, loose aggregations around the exposed outer reefs of isolated oceanic islands. They are prolific inland and around the shores of the Ascension Island area.

Black Durgon are a Benthopelagic species that are also encountered alone and in small, loose aggregations in shallow lagoons, open water, and more abundantly around oceanic islands on the clear, shallower, 15 to 125 foot deep outer reef crest ledges, slopes and drop offs.

In open waters at depths to 300 feet, large congregations of Black Triggerfish are commonly encountered feeding on zooplankton, phytoplankton, and calcareous algae.

Black Triggerfish (Melichthys niger)

Black Triggerfish have a mottled dark blue green, almost black, body color with horizontal markings and occasionally some greenish orange at the head; bold, bright white to bluish white lines along the base of their dorsal and anal fins, and a slightly rounded to double emarginate black caudal fin. Around the eyes and face there are thin, light blue to turquoise colored lines. There are no obvious sexual differences between males and females.

Unlike the Indian Triggerfish (Melichthys indicus), which has never been seen near Hawaii, the Black Durgon lacks the white edging on the caudal fin. Black Triggerfish are capable of changing their colors at will, depending on their mood and surroundings.

Black Triggerfish are not reef safe and will munch on corals and invertebrates in your tank, they are best housed in a mature FOWLR tank of at least 125 gallon capacity with a crushed coralline gravel or sandy substrate, plenty of live rock arranged into caves, crevices, and overhangs and plenty of free swimming space.

Like most triggerfish, Black Triggerfish are voracious eaters that require a good filtration system, efficient protein skimming, and a wave maker to replicate the brisk water movement they require.

Black Triggerfish are territorial and known to be somewhat aggressive, especially towards smaller tank mates and those with similar body shapes.

Similar sized semi aggressive species and slightly smaller more aggressive species can usually coexist with them.

In large systems, suitable tankmates include large angelfish like the Emperor Angelfish (Pomacanthus imperator), some tang species like the Naso Tang (Naso Lituratus), Butterflyfish (Chaetodontidae family), and certain surgeonfish like the  . Avoid housing them with small docile species.

Melichthys niger have not been bred in an aquarium environment.

In the wild like Indian Triggerfish, they are egg scatterers that display distinct pairing during breeding.

Black Triggerfish are omnivores that feed predominately on drifting zooplankton, phytoplankton, squid, shrimp, small fish, calcareous algae, and at Fernando de Noronha Archipelago in the southeast Atlantic, the feces and vomits of Spinner dolphins (Stenella longirostris) that congregate in the shallow bay.

In an aquarium environment, Black Triggerfish require a varied diet of high quality marine pellets, frozen foods, and live or frozen seafood. Frozen Angelfish formulas, vitamin enriched brine shrimp, Spirulina enriched brine shrimp, Mysis, squid, chopped shrimp, mussels, small fish and some vegetable matter will keep them healthy and vibrant.   Feed small portions several times daily.

Black Triggerfish (Melichthys niger) are occasionally available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at prices that vary according to size and area of collection.

Approximate purchase sizes vary from small specimen 1.25″ – 1.75″, up to large 7″ – 9″ adults with prices starting at $75.99 for small specimens.

Black Triggerfish (Melichthys niger)

Minimum Tank Size: 125 gallons
Aquarium Type: FOLR
Care Level: Easy
Temperament: Aggressive
Aquarium Hardiness: Hardy
Water Conditions: Temp 76-82F, dKH 8 – 12°, pH 8.1-8.4, Salinity 1.022-1.025
Max size: 12 – 18″
Color Form: Black, Blue, White
Diet: Omnivore
Compatibility: Not reef safe
Origin: Tropical Pacific to Indian Ocean
Family: Balistidae
Lifespan: Over 10 – 15 years
Aquarist Experience Level: Intermediate

Indian Trigger (Melichthys indicus)

Indian Trigger (Melichthys indicus) known to tropical fish keeping enthusiasts as Black Finned Triggerfish or Indian Black Triggerfish are found throughout the Indian Ocean.   Its range extends from the Red Sea and East Africa, eastward to western Thailand and Sumatra, Indonesia, and the Great Barrier Reef in Australia. Indian triggerfish have never been found near Hawaii.

The Indian Trigger is a solitary species that is usually encountered alone in clear lagoons and along the coral rich seaward reef slopes of their range at depths to 100 feet where they have been observed feeding on algae, sponges, crustaceans, and invertebrates. Along the deep outer reef slopes, lone Indian Triggers are frequently seen as deep as 250 feet feeding on benthic invertebrates.

Juvenile Indian Triggers are often collected from corals and rocks that they shelter among. At night both adults and juveniles have been observed digging holes below the bases of corals and using their dorsal and anal fins to bury themselves with sand to hide from predators.

Indian Trigger (Melichthys indicus)

The Indian Trigger has an oval shaped dark brown, to bluish violet, to black colored body with pale blue, pink, or white stripes along the base of the dorsal and anal fins; white bands that begin at the eyes and extend over most of their face with an oblique blue stripe on the lower cheek, and a narrow white margin on the round caudal fin.

They closely resemble the Black Durgon or Hawaiian Black Triggerfish (Melichthys niger) that lack the white margin on the caudal fin.

The Indian Trigger can be housed in a mature reef or FOWLR tank of at least 150 gallon capacity with a sand or coralline substrate, plenty of live rock arranged into caves, crevices, and overhangs for them to hide among and a copious amount of free swimming space. The Melichthys niger can be kept with caution in reef systems without sponges, gastropods and crustaceans.   They typically do not nip at corals and will generally ignore sessile invertebrates, but adults will eat any ornamental shrimp or snails they may come across.

Indian Triggers are known to be somewhat aggressive, especially towards smaller tank mates and those with similar body shapes.   Ideally, only one Indian Trigger should be kept in a FOWLR tank, however, similar sized semi aggressive species and slightly smaller more aggressive species usually get along well with them.   Avoid housing them with small docile species.

Like most triggerfish, Indian Triggers are voracious eaters that require a good filtration system, efficient protein skimming, and a wave maker to replicate the brisk water movement they require.

The Indian Trigger has never been successfully bred in an aquarium environment.

In their natural environment, Melichthys indicus display distinct pairing when spawning.   The eggs and sperm are simultaneously released into the water column and broadcast onto the substrate.   The parents are very aggressive over their eggs and apparently guard them until they hatch into larvae.

In their natural habitat, Indian Triggers feed on algae, sea weeds, hard shelled mollusks, echinoderms, small fish, zooplankton, and benthic invertebrates like sea urchins, sea worms and small crustaceans.

In an aquarium environment, they should be fed a varied diet of fresh or frozen Angelfish formulas, vitamin enriched brine shrimp, Spirulina enriched brine shrimp, Mysis, squid, chopped shrimp, mussels, small fish and some vegetable matter. Feeding small portions several times daily is recommended.

The Indian Trigger (Melichthys indicus) is occasionally available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at prices that vary according to size and area of collection.

Approximate purchase sizes vary from small specimen 1.0″ – 1.5″, up to large 7″ – 9″ adults with prices ranging from $79.99 to $695.99.

Indian Trigger (Melichthys indicus)

Minimum Tank Size: 150 gallons
Aquarium Type: FOLR
Care Level: Easy to Moderate
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: Temp 72-82F, dKH 8 – 12°, pH 8.1-8.5, Salinity 1.022-1.026
Max size: 9.5″
Color Form: Black, Blue, White
Diet: Carnivore
Compatibility: Not reef safe
Origin: Indian Ocean, West Pacific
Family: Balistidae
Lifespan: Over 10 years
Aquarist Experience Level: Intermediate

Sohal Tang (Acanthurus sohal)

Sohal Tang (Acanthurus sohal) known to tropical fish keeping enthusiasts as Arabian Tang, Sohal surgeonfish, Zebra Surgeon, Majestic Tang, Majestic Surgeon, Zebra tang, or Red Sea Clown Surgeon is found in the northwestern Indian Ocean where its range extends to the Red Sea, east along the coast of the Arabian Peninsula, to the Persian Gulf.

Sohal Tangs found in the Mediterranean during 2017 and 2017 were either released there by tropical fish keeping enthusiasts or by Lessepsian migration through the Suez Canal.

Sohal Tang are a normally encountered alone or in small schools along the shallower lagoons, outer coral reef flats of their range exposed to surges, rocky formations where they graze on a variety of algae that grow on the hard substrates including Sargassum, filamentous green algae, and a variety of other algae at depths to around 65 feet or more.

Acanthurus sohal are a common solitary species that are extremely territorial of their grazing grounds. Despite being a solitary species, they will frequently school to patrol the boundaries of individual grazing territories from other fish.

Sohal Tang (Acanthurus sohal)

Sohal Tang has a body depth about half of its length. The body is a stunning light blue to blue gray color with dark blue to black longitudinal stripes that begin at the forehead, become squiggly behind the eye, and become broader until they join together at the orange scalpel at the caudal peduncle.

The lower head and ventral surface of the body are pale blue with faint gray or greenish grey longitudinal lines. There is an orange splotch behind the bright yellow splotched pectoral fins, with most of the fins being jet black outlined with vivid electric blue. The sharp boney scalpel on the caudal peduncle of the lunate tail is said to be venomous in this species.

Because of their large adult size, the Sohal Tang should be housed alone in a FOWLR or reef tank of at least 250 gallon capacity with a coralline or sandy gravel substrate, plenty of mature live rock arranged into caves, crevices, and overhangs for them to hide among, and a lot of free swimming space. In order to maintain exceptional water quality; a wave maker for a strong water flow and an efficient protein skimmer for waste removal is essential.

The Sohal Tang is primarily a herbivore and is generally considered reef safe, however, they feed on many species of algae which may include desirable coralline algae in the system as well as some species of soft and hard corals. Caution should be exercised before including them in a well-established reef tank with abundant macroalgae.

Sohal Tangs are only suited for very large aquariums with species capable of handling their aggressive and domineering nature. Juveniles are generally well behaved with existing tank mates but can be aggressive to any new additions. It is best not to house them with other Tangs.

Some tank mates that are not likely to provoke aggression include Purple Firefish (Nemateleotris spp.), Six-Line Wrasse (Pseudocheilinus hexataenia), Coral Beauty Angelfish (Centropyge bispinosa),
Bristletooth Tomini Tang (Ctenochaetus tominiensis), and Blue Green Chromis (Chromis viridis).

When setting up a new system, Acanthurus sohal should be the last fish introduced into the aquarium.

The Sohal Tang is generally not available through aquaculture and has not yet been bred in an aquarium environment.

In their natural habitat the Sohal Tangs diet primarily consists of algae.   In an aquarium environment, they should be fed a varied diet of high quality marine pellets, marine algae sheets on a veggie clip, seaweeds, and occasionally fresh or frozen enriched brine shrimp, mysis shrimp, or chopped shrimp. Several feedings daily of small portions are recommended.

The majority of Sohal Tang (Acanthurus sohal) available to tropical fish keeping enthusiasts are caught by net in the wild. They are occasionally available on waiting lists through specialty fish shops, wholesalers and online retailers like Saltwaterfish.com at approximate purchase sizes: Small: 1″ to 2″; Small/Medium: 2″ to 2-3/4″; Medium: 2-3/4″ to 3-1/2″; Medium/Large: 3-1/2″ – 4″ Large: 4″ to 5″.

Prices start at around $349.99 for small to medium size specimens.

Sohal Tang (Acanthurus sohal)

Minimum Tank Size: 250 gallons
Aquarium Type: Reef or FOLR
Care Level: Moderate
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 74-80° F, , dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 16″
Color Form: Black, Blue, Green, Yellow, Orange
Diet: Herbivore
Compatibility: Reef safe
Origin: Red Sea and Western Indian Ocean
Family: Acanthuridae
Lifespan: 7-10 years
Aquarist Experience Level: Intermediate

Crosshatch Triggerfish (Xanthichthys mento)

Crosshatch Triggerfish (Xanthichthys mento) known to tropical fish keeping enthusiasts as the Blue Cheekline Trigger, Redtail Triggerfish, or (erroneusly) the Blue Throat Triggerfish is found throughout tropical and sub-tropical Eastern and Western Pacific Oceans. Its range extends from southern Japan, Hawaiian Islands, Clipperton Island, Revillagigedo Islands, to southern California, Easter Island, and Pitcairn Islands.

Crosshatch Triggerfish are one of the rarer benthopelagic species that are encountered in large schools around corals, rocky substrates, drop-offs, and areas with ample hiding spots along the outer seaward coral reefs of oceanic islands and continental slopes of their range at depths from 20 to over 430 ft.   They are often found in large schools in open water, usually at depths below 90 feet, feeding on passing zooplanktons.

Crosshatch Triggerfish have the typical triangular shape of other Triggerfish when its fins are erect, similar to other members of the genus Xanthichthys.

Crosshatch Triggerfish (Xanthichthys mento)

Males have straw yellow colored scales outlined in black, that give the body an intense yellow crosshatched look, and a red rimmed tail with neon blue submarginal bands. Females are distinguished by a yellow fringed caudal fin and a slate gray to drab blue body color that runs into the caudal fin. Both sexes have black cris-crossing lines along the body and blue radiating lines on the face.

Because of their innate foraging behavior, Crosshatch Triggerfish, like the Humu Rectangle Triggerfish (Rhinecanthus rectangulus) are not considered reef safe. They will constantly rearrange and disturb rocks and corals in a reef system and prey on invertebrates and crustaceans, making them much more suited for FOWLR tanks.

Crosshatch Triggerfish are best housed in a mature FOWLR tank of at least 125 gallon capacity with a sand or coralline gravel substrate, substantial amounts of live rock formed into caves, crevices, and overhangs for them to hide among, and plenty of free swimming space along the substrate. A good filtration system, protein skimmer and wave maker to replicate the moderate currents in their natural habitat is recommended.

Crosshatch Triggerfish can be housed singly, in pairs, or in groups of one male and two or more females. They have a mild disposition and are unlikely to conflict with other aquarium inhabitants in a large system. Except for small Pseudochromis and other smaller species, they mix well with most other reef fish.

Suitable tankmates that can can coexist with Crosshatch Triggerfish include large angelfish like the Emperor Angelfish (Pomacanthus imperator), peaceful herbivores like Yellow Tangs (Zebrasoma flavescens), Flame Angelfish (Centropyge loricula), Hawaiian Cleaner Wrasse (Labroides phthirophagus), Sohal Tang (Acanthurus sohal), basslets, and other hardy species.

Crosshatch Triggerfish are not commonly aquacultured and have only recently been bred in an aquarium environment.   Their relative rarity in the aquarium trade and high, dependable, embryo production make the challenging to raise larvae a worthwhile effort for breeders. Juveniles were successfully raised from captive eggs on ciliates, copepods and artemia.

In their natural habitat, Xanthichthys mento live singly, as pairs, and in small groups or larger schools. They are demersal spawners that become highly territorial during courtship and spawning.   Males will establish a territory for spawning to take place which is normally during the early morning hours.

After spawning, anywhere from a thousand to a million 0.48 mm diameter fertilized eggs are scattered along the bottom. The spherical, adhesive eggs that contain multiple oil droplets hatch in the evening into small larvae that begin feeding at 2.1 mm in length. Although both parents guard the offspring, only the females tend to the eggs. In an aquarium environment, the larval stage lasts anywhere from 65 to over 100 days. Crosshatch Triggerfish pairs will spawn approximately every 19-23 days.

In their natural habitat, Crosshatch Triggerfish are an opportunistic benthopelagic species that live and feed near the bottom on benthic, in midwater on passing zooplanktons, and near the surface on a variety of free swimming organisms.

In an aquarium environment, they are not finicky eaters and will consume most aquarium fare including high quality marine pellets, frozen foods, and live or frozen seafood to maintain their health and vibrancy.

Their diet should primarily consist of meaty foods like fresh or frozen chopped whole shrimp, squid, silver sides, mysis shrimp, and clams. Chopped krill is an especially good food that provides the beneficial carotenoids needed to maintain their pigmentation. Feeding small portions several times daily is recommended to maintain body weight.

Crosshatch Triggerfish (Xanthichthys mento) known for their striking colors and intricate pattern of lines are a popular choice among tropical fish keeping enthusiasts. Although they are relatively rare and expensive, thay are occasionally available on waiting lists through specialty fish shops and online retailers like Saltwaterfish.com.

Current prices for 4″ to 5″ males start at around $1300.99.

Crosshatch Triggerfish (Xanthichthys mento)

Minimum Tank Size: 125 gallons
Aquarium Type: FOLR
Care Level: Easy
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 76 to 82°F , dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 12″
Color Form: Black, Blue, Red, Yellow
Diet: Omnivore
Compatibility: Not reef safe
Origin: Indo Pacific
Family: Balistidae
Lifespan: 8 – 12 years
Aquarist Experience Level: Intermediate

Rectangle Triggerfish (Rhinecanthus rectangulus) known to tropical fish keeping enthusiasts as the Reef Triggerfish, Patchy Triggerfish, Rectangular Triggerfish, Wedge Picassofish, Wedge Tailed Trigger, or V-line Humuhumunukunukuapuaa, is found throughout the Indo West and Central Pacafic, and is the state fish of Hawaii.

The Humu Rectangle Triggerfish range extends from the Red Sea south to East London, South Africa and east through Indonesia to the Marquesan Islands and northern Australia up to Hawaii and Pitcairn islands, north to southern Japan, and south to Lord Howe Island.

Humu Rectangle Triggerfish are benthopelagic, generally solitary, and extremely territorial.

Adult Humu Rectangle Triggerfish are commonly found over barren rock as well as mixtures of bare rock, rubble, and coral situated along the shallow outer reefs and lagoons of their range which are subject to surges, at depths to 70 feet where they are often seen feeding on algae, detritus, echinoderms, mollusks, crustaceans, worms, fishes, sponges, foraminifera, and fish eggs.

Juvenile Rhinecanthus rectangulus are more commonly found on shallower algae reef roofs.

Humu Rectangle Triggerfish (Rhinecanthus rectangulus)

Humu Rectangle Triggerfish have an orange brown body color with a white head and belly; a pearly white face with two blue and black stripes across the eyes, a blue bar across the upper lip, a diagonal black V shaped band outlined in yellow that runs from the eye to the anal fin, and a black wedge shaped mark, preceded by two yellow V shaped marks on the caudal peduncle. The soft dorsal, anal, and pecroal fins are a pale dusky color. In juveniles, the yellow V shaped marks on the caudal peduncle are white.

Like Niger Triggerfish, adult and juvenile Rhinecanthus rectangulus have the ability to rapidly alter their coloration when sleeping or changing their moods. Their colors are most vivid when healthy and unthreatened but become drab in appearance when sleeping or demonstrating submission.

Humu Rectangle Triggerfish are not reef safe and do best housed in mature FOWLR tank of at least 180 gallon capacity with a sand or coralline gravel substrate, substantial amounts of live rock formed into caves, crevices, and overhangs for them to hide among, and plenty of free swimming space. A good filtration system, protein skimmer and wave maker to replicate the moderate to strong currents in their natural habitat is recommended.

Rhinecanthus rectangulus are pretty aggressive and generally will not tolerate conspecific individuals in their general vicinity. They do best with other larger semi aggressive species and should never be housed with smaller peaceful or docile species.

Although some tropical fish keeping enthusiasts have had success keeping Humu Rectangle Triggerfish in very large reef tanks without crustaceans and invertebrates, they constantly rearrange rocks and corals as they search for benthic invertebrates under the substrate, sifting and spitting sand over their surroundings.

Humu Rectangle Triggerfish are difficult to sex and have not been bred in an aquarium environment.

In their natural environment, Reef Triggerfish are omnivores that have a diverse diet.

They feed on algae, detritus, crustaceans like crab, shrimp, and lobster; mollusks like octopus and squid; worms and planktonic organisms, and smaller fish like sardines and anchovies.

In an aquarium environment, they require a varied diet of high quality marine pellets; live, fresh, or frozen squid, krill, clams, mussels, shrimp, Mysis, octopus, snails, scallops, and especially hard shelled shrimp to help wear down their teeth. Feeding small portions several times a day is recommended to a single large feeding.

Humu Rectangle Triggerfish (Rhinecanthus rectangulus) are available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at prices that vary according to size and area of collection.

Approximate purchase sizes: Small: 1″ to 2″; Medium: 2″ to 3-1/2″; Large: 3-1/2″ to 5″; X Large: 5″ to 6″; XX Large: 6″ to 8″.

Prices for small specimens start at around $49.99 for Sumatran specimens and increase to over $125.99 for large specimens.

Humu Rectangle Triggerfish (Rhinecanthus rectangulus)

Minimum Tank Size: 180 gallons
Aquarium Type: FOLR
Care Level: Easy to Moderate
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-78° F, dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 12″
Color Form: Black, Blue, Orange, White, Yellow
Diet: Carnivore
Compatibility: Not reef safe
Origin: Indo West and Central Pacific
Family: Balistidae
Lifespan: Over 15 years
Aquarist Experience Level: Intermediate

Blue Throat Triggerfish (Xanthichthys) breeding

Blue Throat Triggerfish (Xanthichthys auromarginatus) known to tropical fish keeping enthusiasts as Blue Jaw Triggerfish, Gilded Triggerfish or Blue Chin Triggerfish are found throughout the Indo-Pacific, East Africa to Hawaii.

Their range extends in the Indo Pacific from the Mauritius eastward through northern Australia to the Hawaiian and Society islands, north to southern Japan.

Blue Throat Triggerfish are usually encountered in loosely formed groups of their range around the rocky ledges and drop offs of current swept seaward reefs that are rich in invertebrate growth, where they feed on copepods and other zooplankton near the bottom.

Although Blue Throat Triggerfish are Benthopelagic and have been collected at depths from 25 to 500 feet, they are more commonly found in small aggregations at moderate depths from 60 to 480 feet hovering several feet above the ocean floor.

Blue Throat Triggerfish (Xanthichthys auromarginatus)

Male and female Xanthichthys auromarginatus are easily identifiable.   Males have a grayish blue body color with gray to white spots in an interesting linear pattern, metallic blue rings around the eyes, a blue throat, and dorsal, anal, and caudal fins outlined in bright yellow. Females lack the blue throat and yellow bordering on the fins.

Blue Throat Triggerfish are a relatively docile species that can be housed with other similarly sized fish in a mature FOWLR or reef tank of at least 180 gallon capacity with a sandy or coralline substrate, plenty of live rock arranged into caves, crevices, and overhangs for them to hide among with plenty of free swimming space.

They require a good filtration system with sufficient protein skimming and a wave maker for moderately strong water movement.

Although they are considered reef safe and ignore corals and sessile invertebrates, being triggerfish, they will go after smaller fish, ornamental shrimp, and other crustaceans.

Blue Throat Triggerfish can be housed in small groups of one male and two or more females, however, keeping more than one male in a tank is not recommended.

Xanthichthys auromarginatus are seldom successfully bred in an aquarium environment.

Like Melichthys vidua, Blue Throat Triggerfish pair up to build nests to deposit their eggs. Males and females guard their eggs against predators until the larvae are hatched out.

Due to lack of a sufficient food source, triggerfish larvae bred in captivity normally do not survive, however, a new type of food has recently been developed for tropical fish keeping enthusiasts that is expected to make aquarium breeding of these species more successful.

In their natural habitat, Blue Throat Triggerfish feed primarily on copepods.   In an aquarium environment, they do well on a mixed diet of meaty foods including fresh or frozen Mysis shrimp, squid, clams, krill, sponge, small fish, and vitamin or Spirulina enriched brine shrimp. They will also accept marine omnivore pellets and dried seaweed on a veggie clip if you have tangs in the tank. Feeding a balanced diet including flake, pellets, frozen meaty foods, and herbivorous foods will keep them healthy.

Blue Throat Triggerfish (Xanthichthys auromarginatus) are available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at prices that vary according to size and area of collection from $60.99 – $299.99.

Blue Throat Triggerfish (Xanthichthys auromarginatus)

Minimum Tank Size: 180 gallons
Aquarium Type: FOLR
Care Level: Easy
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-82° F, dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 12″
Color Form: Blue, Gray, Yellow
Diet: Omnivore
Compatibility: Reef with Caution
Origin: IndoPacific, East Africa to Hawaii
Family: Balistidae
Lifespan: Over 8 years
Aquarist Experience Level: Intermediate

Pinktail Triggerfish (Melichthys vidua)

Pinktail Triggerfish (Melichthys vidua) known to tropical fish keeping enthusiasts as Red-Tailed Triggerfish are found throughout Indo Pacific waters. Their range extends from East Africa eastward through the entire length of the Great Barrier Reef in northwestern to central Australia, to the Hawaiian and Tuamotu islands westward through Polynesia, Micronesia, the Philippines, and the East Indies, and north to southern Japan.

Pinktail Triggerfish are frequently encountered in loose groups grazing on algae, sponges, crustaceans, detritus, small fish and octopuses at depts from 6 to over 190 feet where strong currents abide the on coral rich seaward reefs. They can be found anywhere there is an abundance of invertebrates.

Pinktail Triggerfish (Melichthys vidua)

Pinktail Triggerfish have a dark (almost black), emerald green body with yellow accents at the face, translucent pinkish white dorsal and anal fins that are edged with dark bands, and yellowish colored pectoral fins. The caudal fin is a bright pink to pinkish white color, hence its common name. Visually, there is no sexual difference between males and females.

Pinktail Triggerfish require a large established FOWLR or reef tank of at least 180 gallon capacity with a sandy or coralline substrate and plenty of

arranged into caves, crevices and overhangs for them to hide among. Like all triggerfish, they need plenty of free swimming space.

Pinktail Triggerfish are a shy, inquisitive, peaceful species that become quite docile and outgoing over time.   Although they are seldom aggressive toward tank mates of the same size, they will eat much smaller fish. If more than one specimen is being housed in a large system, it is best to add a single male with several females at the same time.

Melichthys vidua are considered reef safe, however, they enjoy rearranging live rock and sometimes corals in their tank.   Although Sessile invertebrates are largely ignored, they should definitely not be housed with snails, crabs, ornamental shrimp, and tiny or very shy fish.

Because Pinktail Triggerfish eat a great deal and are quite messy, they require a good filtration system with adequate protein skimming and a wave maker for moderately strong water movement.

Red-Tailed Triggerfish have rarely been successfully bred in an aquarium environment.

In their natural environment, Melichthys vidua pair up and build nests to deposit their eggs.   Males and females guard their eggs against predators until the larvae are hatched out.   Due to lack of a sufficient food source, triggerfish larvae bred in captivity will normally not survive, however, a new type of food has recently been developed for Triggerfish larvae that is expected to make aquarium breeding of these species more successful.

In the wild, Pinktail Triggerfish are voracious eaters that feed on algae, detritus, crustaceans, octopuses, sponges, small fish, and almost any food.

In an aquarium environment, they need a varied diet of meaty foods including fresh or frozen Mysis shrimp, squid, clams, krill, sponge, small fish, vitamin and Spirulina enriched brine shrimp, and harder foods like shelled shrimp or snails to help wear down their teeth. Feeding small portions two to three times daily is recommended.

Pinktail Triggerfish (Melichthys vidua) are available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at prices that vary according to size and area of collection.

Approximate purchase sizes: Small: 1-1/2″ to 2-1/2″; Small/Medium: 2-1/2″ to 3″; Medium 3″ to 4″; Medium/Large: 4″ to 5″; Large 5″ to 7″; XLarge: 7″ or Larger

Prices for small specimens start at around $149.99 for Indonesian specimens and increase to over $269.99 for extra large specimens.

Pinktail Triggerfish (Melichthys vidua)

Minimum Tank Size: 180 gallons
Aquarium Type: FOLR
Care Level: Moderate
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-78° F, dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 15″
Color Form: Green, Red, Yellow
Diet: Carnivore
Compatibility: Reef with Caution
Origin: Polynesia, Micronesia, the Philippines, East Indies, Africa
Family: Balistidae
Lifespan: Over 10 years
Aquarist Experience Level: Intermediate

Niger Triggerfish (Odonus niger)

Niger Triggerfish (Odonus niger) known to tropical fish keeping enthusiasts as Black Triggerfish, Red Tooth Triggerfish, Blue Triggerfish, Redfang Triggerfish, and Redtoothed Filefish are found throughout Indo-Pacific waters and the Red Sea. Their range extends from the east coast of Africa to the Marquesas and Society islands, as far north as Japan, and as far south as the Great Barrier Reef in Australia.

Niger Triggerfish (Odonus niger)

Niger Triggerfish are frequently found between the rocks and crevices of long slopes and fast flowing reef channels of their range at depths from 30 to over 100 feet where they feed primarily on copepods and sea sponges. In the shallower inshore coastal waters, adult Niger Triggerfish are often encountered in large groups as they feed on zooplankton carried by the swift currents.

Although Niger Triggerfish have a deep purple body with bluish green markings on their heads, hints of yellow on their throat, and glowing light blue margins on their lyre tail lobes and fins, they change colors depending on their moods. Colors range from blue, to blue green, to black, to purple. Niger Triggerfish have tiny red needle sharp teeth, a mouth that looks like it is constantly grinning at you, and small pectoral fins. They locomote with their dorsal and anal fins in an undulating motion unique to this species.

A single Niger Triggerfish can be housed in a mature FOWLR or reef tank of at least 180 gallon capacity with a sand or coralline substrate, plenty of live rock arranged into caves, crevices, and overhangs for them to hide among, and a lot of free swimming space.   Although they are NOT considered reef safe, tropical fish keeping enthusiasts have successfully housed them in large reef tanks with a minimum of crustaceans. Even though they do not eat corals, Odonus niger may use coral rubble, sponges, snails, tunicates, and any crustacean they can find to sharpen their red teeth. They also have a habit of overturning live rock in the tank which can damage corals.

In a FOWLR tank, Niger Triggerfish may fight with other triggers but they normally do fine with similarly sized fish such as tangs. The larger they get, the more aggressive they become. Female to female aggression is common with Odonus niger.

To date, Niger Triggerfish have not been bred in an aquarium environment.

In the wild, Nigers are nest builders. The males set up territories in the mating grounds where they lay the eggs in their nests. The females care for the eggs while both parents guard the eggs until the larvae hatch out.

Redtoothed triggerfish are planktivorous feeders that also eat krill, clams, squid, sea urchins, and small fish. In an aquarium environment, they will eat anything, but a balanced diet of meaty foods like clams, Krill, frozen mysis shrimp, brine shrimp, and frozen omnivore foods is recommended. Feed them two to three times daily in lieu of a single feeding.

Niger Triggerfish (Odonus niger) are available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at reasonable prices that vary according to size and area of collection.

Approximate purchase sizes: Small: 1″ to 2″; Medium: 2″ to 3″; Medium/Large 3″ to 3 3/4″; Large: 3 3/4″ to 4 1/2″; X Large 4 1/2″ to 5 1/2″.   Prices for small specimens start at around $ 69.99 and increase to $259.99 for extra large specimens.

Minimum Tank Size: 180 gallons
Aquarium Type: FOLR
Care Level: Moderate
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 76-82° F, dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 12 – 18″
Color Form: Purple, Blue green, Blue
Diet: Omnivore
Compatibility: Reef with Caution
Origin: Indo Pacific, Australia, Fiji, Indonesia, Sri Lanka
Family: Balistidae
Lifespan: Over 10 years
Aquarist Experience Level: Intermediate

Sargassum Triggerfish (Xanthichthys ringens)

Sargassum Triggerfish (Xanthichthys ringens) known to tropical fish keeping enthusiasts as the Red Tail Triggerfish which is also occasionally applied to the Crosshatch Triggerfish (Xanthichthys mento), is found in the Western Atlantic from South Carolina, through the Gulf of Mexico to Lesser Antilles and Brazil.

Adult Sargassum Triggerfish are normally found alone or in small groups along floating sargassum and most often along the seaward reef slopes of their range at depths from 80 to over 260 feet where they can be seen feeding on crabs, shrimp, sea urchins, and zooplankton.

Juveniles Sargassum Triggerfish are frequently found hiding among clumps of floating Sargassum where they reside until fully developed, hence their common name.

Sargassum Triggerfish (Xanthichthys ringens)

Sargassum Triggerfish have a light brownish gray to blue body color with rows of dark brown spots along the sides. They have three diagonal silvery blue to brown colored grooves on the face that start just behind and below the mouth and run almost to the gill openings. The pale caudal fin is bordered orange/red, and a large orange/red crescent edges the end of the tail. The dorsal and anal fins are also bordered an orange/red.  Females are more drab in color.

Sargassum Triggerfish are a reef friendly species that require a large established FOWLR or reef tank of at least 125 gallon capacity with a sandy or coraline substrate with rubble and seashells and plenty of live rock arranged into caves, crevices and overhangs for them to hide among. Like all triggerfish, they need plenty of free swimming space.

Although Sargassum Triggerfish are considered reef safe, they will turn over rocks, rubble, benthic invertebrates, and corals in search of prey.   Although Sessile invertebrates are largely ignored, they should definitely not be housed with crustaceans, especially ornamental shrimp. Providing a deep sand bed mixed with rubble and seashells for them to turnover while foraging keeps them occupied.

Red Tail Triggerfish can be housed singly or in pairs however, they should only be kept with larger fish that are not easily harassed.

Like all triggerfish, Xanthichthys ringens requires stable water conditions and a varied diet to thrive. An excellent protein skimmer and/or a wet dry filtration system along with a wave system to maintain water quality and movement is highly recommended. Because this species is commonly found at deeper depths, water temperature should be kept below 80°F.

Sargassum Triggerfish have not been bred in an aquarium environment.

Red Tail Triggerfish are carnivores that prey on small fish, starfish, crabs, shrimp, snails and sea urchins. In an aquarium environment they do well on meaty diets that include krill, shrimp, squid, and scallops. They will accept pellet and flake foods. Feeding Sargassum Triggerfish small portions two to three times a day is recommended.

Sargassum Triggerfish (Xanthichthys ringens) are seasonally available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at reasonable prices that vary according to size. This species is available captive bred.

Sargassum Triggerfish (Xanthichthys ringens)

Minimum Tank Size: 125 gallons
Aquarium Type: FOLR
Care Level: Easy
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-78° F, dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 9.8″
Color Form: Tan, Red, Blue
Diet: Carnivore
Compatibility: Reef with Caution
Origin: Western Atlantic
Family: Balistidae
Lifespan: 20 to 30 years
Aquarist Experience Level: Intermediate

Picasso Triggerfish (Rhinecanthus aculeatus)

Picasso Triggerfish (Rhinecanthus aculeatus) known to tropical fish keeping enthusiasts as Humuhumu Triggerfish (the official state fish of Hawaii), Blackbar Triggerfish, Lagoon Triggerfish, or Picassofish is found throughout the Indo-Pacific and ranges from East Africa eastward through northern Australia to the Hawaiian, Marquesas, and Tuamotu islands, north to southern Japan.

Picasso Triggerfish are a shy, highly territorial species that are most commonly found in the subtidal reef flats and shallow protected lagoons of their range at depths from 3 to over 160 feet where they can be seen grazing on detritus, mollusks, crustaceans, sea urchins, worms, algae, corals, tunicates, forams, small fishes, eggs, and just about anything they come across.

Adults prefer open flat, sandy areas of the reef with scattered patches of rubble, while the more secretive juveniles are found hiding in rocky rubble.

Picasso Triggerfish (Rhinecanthus aculeatus)

Picasso Triggerfish have a large oval shaped body with small, prominent eyes, and strong jaws that are used for opening up shells and corals.

Picasso Triggerfish colors are a true work of art of light tans, whites and painted splashes of yellow, blue, black, and brown.

They have a grayish tan body color with dark gradients towards the rear and a bright white belly.   The top of the head above the eye is covered with bright blue and black stripes, the small prominent orange or yellow eyes sit at the top of the head, and a bright yellow or black stripe runs from the mouth towards the lower portion of the body, just above the white belly and ends below the eye.

Picasso Triggerfish require a spacious FOWLR tank of at least 180 gallon capacity with a sandy or coraline substrate, and plenty of live rock arranged into caves, overhangs, crevices, for them to hide among.

Rhinecanthus aculeatus are NOT reef safe.   They can be very aggressive towards fish and invertebrates and although they may not initially bother any corals in the tank, they will greedily eat larger crabs, sea urchins, and shrimp.   Some tropical fish keeping enthusiasts have had luck keeping Humuhumu Triggerfish in full reef setups when introduced as juveniles, but their aggression grows with age.

Picasso Triggerfish are best housed alone or with other aggressive species in a fish only tank.

Like all triggerfish, this species requires stable water conditions, a varied diet, and constant monitoring of their behavior.

An excellent protein skimmer and wet dry filtration system is required along with a wave system to maintain water quality and movement.

Picasso Triggerfish display distinct pairing and have been bred in an aquarium environment but success is challenging and rare.

Mating is a mixture of polygyny, monogamy, and promiscuity; with polygyny being the primary mating process.

Both sexes guard and maintain their territories for up to eight years or longer.   A male’s territory may overlap with one to five female territories and their mating system is described as haremic.

Pairs spawn around sunrise.   After external fertilization takes place, the egg masses are attached to the sand, coral rubble, or algae and hatch on the same day around sunset.

The females guard and care for eggs until they hatch.   She stations herself above the eggs and fans them with her pectoral fins for about 12 to 14 hours to improve aeration while aggressively chasing away any intruders, including divers.

Fortunately their relatively small size makes them much less dangerous than the larger Titan Triggerfish or Moustache Triggerfish (Balistoides viridescens) of the same family.

Picasso Triggerfish reproduce multiple times over their lifetimes.

Humuhumu Triggerfish are carnivores that in their natural habitat mainly prey on invertebrates such as snails, crabs, clams, mussels, shrimp, urchins, and about any hard or soft shell animal.   In an aquarium environment they should be fed a varied diet of meaty foods including squid, krill, clams, small fish, mussels, and hard shelled shrimp to help wear down their ever growing teeth.   Feeding Picasso Triggerfish two to three times a day is recommended

Picasso Triggerfish (Rhinecanthus aculeatus) are available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at reasonable prices that vary according to size and area of collection.

Approximate purchase sizes: Small: 1″ to 2″; Medium: 2″ to 3″; Medium/Large 3″ to 3 3/4″; Large: 3 3/4″ to 4 1/2″; X Large 4 1/2″ to 5 1/2″. Prices for small Keynan specimens start at around $ 69.99.

Picasso Triggerfish (Rhinecanthus aculeatus)

Minimum Tank Size: 180 gallons
Aquarium Type: FOLR
Care Level: Easy
Temperament: Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-78° F, dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 10″
Color Form: Black, Blue, Orange, Tan, Yellow
Diet: Carnivore
Compatibility: Reef NO
Origin: Indo-West Pacific and Hawaii
Family: Balistidae
Lifespan: 10 years
Aquarist Experience Level: Intermediate

Undulate Triggerfish (Balistapus undulatus)

Undulate Triggerfish (Balistapus undulatus) known to tropical fish keeping enthusiasts as the Orangelined Triggerfish, Balistapus undulatus, Orangelined – Orangetailed Triggerfish, and Orange-Lined Triggerfish is a demersal species that occurs on coral reefs in tropical marine waters of the Indo-western Pacific.

The Undulate Triggerfish‘s range extends from the coast of East Africa, the Red Sea, Japan, and in Western Australia; from the central to north-western coast, and the entire length of the Great Barrier Reef south to northern New South Wales.

Both juvenile and adult Orangelined Triggerfish have been found at depths to over 160 feet, but they prefer living in the shallower coral reefs, coral lagoons, and external reef slopes at depths from 6 to 35 feet.

Adult Undulate Triggerfish are normally found around their burrows and dens among rock and branching corals, while juveniles prefer softer corals.

The Undulate Triggerfish is an omnivorous demersal species that because of its broad distribution and varied benthic diet is a critical component in coral reef ecosystems. They feed on molluscs, crustaceans, ctenophores, cnidarians, echinoderms, algae, small fish, and are a dominant predator of Echinometra mathaei, the burrowing sea urchin, which can if left unchecked totally degrade a flourishing coral reef ecosystem.

Undulate Triggerfish (Balistapus undulatus)

The Undulate Triggerfish has a stocky, laterally compressed, oval shaped body with a large head, a small mouth, and strong teeth. They have an attractive dark brown to emerald green body with orange lines that begin behind the head and cover the entire body. They have an orange caudal fin with a large black spot at the base of their peduncular spines.

Male Undulate Triggerfish are generally larger than females and do not have concave

Undulate Triggerfish (Balistapus undulatus)

snouts. Juvenile fish and females are smaller and have concave snouits. Males lose the orange lines around their snout as they mature.

Because of its belligerent attitude, the Undulate Triggerfish is best housed in a mature FOWLR aquarium of at least 125 gallon capacity with a sandy of fine coralline gravel substrate and copious amounts of live rock arranged into crevices, overhangs and caves for them to hide among. They are NOT reef safe and should be the only trigger in a fish only aquarium.

Undulated Triggerfish will thrive best either on its own or with other similarly sized, semi-aggressive to aggressive tankmates. They can be shy when first introduced into a community tank but will quickly get over their shyness and eventually attack other less aggressive tankmates, especially triggerfish.

Undulate Triggerfish have not been bred in an aquarium environment.

In their natural habitat, Orangelined Triggerfish are carnivores that feed on fish, mollusks, corals, crustaceans, ctenophores, cnidarians, algae, and especially echinoderms. In an aquarium environment they should be fed a varied diet of fresh or frozen shrimp, squid, clams, small fish, krill, hard shelled rock shrimp as well as some marine algae and vitamin-enriched herbivore foods.

Undulate Triggerfish (Balistapus undulatus) is readily available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at reasonable prices that vary according to size and area of collection.

Approximate Purchase Sizes: Under 2″; Medium: 2″ to 4″; Large: 4″ or Higher. Medium size Indonesian prices start at $89.99.

Undulate Triggerfish (Balistapus undulatus)

Minimum Tank Size: 125 to 180 gallons
Aquarium Type: FOLR
Care Level: Easy
Temperament: Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-78° F, dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 12″
Color Form: Black, Blue, Green, Orange, Yellow
Diet: Carnivore
Compatibility: Reef NO
Origin: Indo-West Pacific and Hawaii
Family: Balistidae
Lifespan: 8 – 10 years
Aquarist Experience Level: Intermediate

Bursa Triggerfish (Rhinecanthus verrucosus).

The Bursa Triggerfish (Rhinecanthus verrucosus) known to tropical fish keeping enthusiasts as the Black Patch Triggerfish or Blackbelly Triggerfish occurs on coral reefs throughout the Indo-West Pacific and in Hawaii. Its range extends from the Seychelles and Chagos Islands to south Japan, Vanuatu, and the Great Barrier Reef in Australia.   In Australia it is recognized from the offshore reefs of north-western Western Australia and from the northern Great Barrier Reef to northern New South Wales.   A probable aquarium release was reportedly observed near Boca Raton, Florida in 1995.

Bursa Triggerfish are most commonly found around the edges of shallow, sandy bottomed reef flats on both the lagoon and seaward sides; among macroalgae, rubble, corals, and seagrasses at depths from 3 to 100 feet where they feed on fish, tunicates, mollusks, crustaceans, sea urchins, and some corals.

Juveniles migrate to the reef flats at high tide and return to the subtidal zone during low tides. They are often collected from holes where they shelter.

The Bursa Triggerfish has a laterally compressed body with a protruding snout with large lips and three rows of forward curving spines on the side of the body at the caudal peduncle.   The dorsal and anal fins are similar in shape and the first dorsal spine can be locked into place, allowing the fish to wedge itself into holes and crevices. When locked, the first spine can be collapsed by pressing on any of the smaller spines.

Bursa Triggerfish (Rhinecanthus verrucosus).

The Bursa Triggerfish is brown to light blue in color, milky white below the lateral line, and grayish brown above a large black circular splotch on the abdomen. The face is half yellow and half white with a red, pencil thin moustache and a colorful yellow, blue, and army green mask across the eyes.

The Bursa Triggerfish is best housed in a mature FOWLR aquarium of at least 125 gallon capacity with a sandy of fine coralline gravel substrate and copious amounts of live rock for them to hide among.

Adult Blackbelly Triggerfish are shy but become territorial and highly aggressive towards other triggerfish.  They have strong teeth and jaws and will readily eat smaller fish, invertebrates, and corals.   They are definitely NOT reef safe and should only be housed with other aggressive species in a community tank.

Rhinecanthus verrucosus have not been bred in an aquarium environment.

In their natural habitat, Blackbelly Triggerfish are carnivores that feed on fish, tunicates, mollusks, crustaceans, sea urchins, and corals.   In an aquarium environment they should be fed a varied diet of fresh or frozen shrimp, squid, clams, fish, krill, hard shelled rock shrimp as well as some marine algae and vitamin-enriched herbivore foods.

The Bursa Triggerfish (Rhinecanthus verrucosus) is readily available to tropical fish keeping enthusiasts from a variety of online suppliers and specialty fish shops at reasonable prices that vary according to size and area of collection. Approximate Purchase Sizes: Small: 1″ to 2″; Medium: 2″ to 3″; Large 3″ to 4″. Medium size prices from Indonesia start at $69.99, and from Phillippines $79.99.

Bursa Triggerfish (Rhinecanthus verrucosus).

Minimum Tank Size: 125 gallons
Aquarium Type: FOLR
Care Level: Easy
Temperament: Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-78° F, dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.023
Max size: 9″
Color Form: Orange, Tan, White, Yellow
Diet: Carnivore
Compatibility: Reef NO
Origin: Indo-West Pacific and Hawaii
Family: Balistidae
Lifespan: 8 – 10 years
Aquarist Experience Level: Intermediate

Tanganyikan Spiny Eel (Mastacembelus ellipsifer)

The Tanganyikan Spiny Eel (Mastacembelus ellipsifer) is a nocturnal benthopelagic predator endemic to Lake Tanganyika in Africa.   Also collected in Burundi, Democratic Republic of the Congo, Tanzania, and Zambia Mastacembelus ellipsifer are only one of the fifteen spiny eel species found in the Tanganyikan basin.

Tanganyikan Spiny Eels are found in the intermediate zones around the shores of Lake Tanganyika where the rocks diverge into sandier substrates.   They prefer coastal waters with a sandy, rock, or a muddy bottom where most of their daylight hours are spent either buried in the substrate with only their snouts visible, or hidden among rocks where they emerge at dusk to forage on small fish, worms, and crustaceans.

Tanganyikan Spiny Eels are named such because of their very hard dorsal fin rays and because they are primarily bottom dwellers, they have no swim bladder.

Tanganyikan Spiny Eel (Mastacembelus ellipsifer)

The Tanganyikan Spiny Eel has an extremely elongated, laterally compressed body with a long distinctively pointed snout and an under-slung mouth.  They have a brownish to beige body color with a dark brown ring shaped pattern on the back.   Males are indistinguishable from females.

Because of their size, Tanganyikan Spiny Eels should be housed in at least a 55 gallon aquarium with a deep sandy or extremely fine gravel substrate and several piles of rocks arranged to form crevices, caves, and overhangs for them to hide among.   A long, wide tank is preferred to a high tank.   Aquatic plants are not necessary for this species and because the sharp edges on gravel can damage the eel’s skin, its use is not recommended as a substrate.

Because of its hard, alkaline water requirements, Tanganyikan Spiny Eels are not suitable for most freshwater aquariums.   They are best housed in a Tanganyikan community tank, combined with species too large to be considered food.   Because they tend to be territorial with conspecifics, a large tank of at least 100 gallon capacity is recommended if more than one is going to be housed.

Mastacembelus ellipsifer does not like strong current in their aquarium.   Because of their nocturnal nature and burying habits, dim lighting is recommended if you want to watch your eel on a regular basis.   A tightly fitting tank cover is also recommended for this species.

Although they are egg depositors, Mastacembelus ellipsifer has not yet been successfully bred in an aquarium environment.

In their natural environment, Tanganyikan Spiny Eels prey almost entirely on small fishes. In an aquarium environment they will eat small feeder fish, fresh or frozen prawn, cockles, mussels, earthworms, and bloodworms.

The Tanganyikan Spiny Eel (Mastacembelus ellipsifer) is occasionally available for purchase online and from specialty tropical fish keeping shops when they are 6″ to 8″ or more in length.

Tanganyikan Spiny Eel (Mastacembelus ellipsifer)

Minimum Tank Size: 55 gallons
Care Level: Moderate
Temperament: Peaceful
Aquarium Hardiness: Hardy
Water Conditions: 73-81° F, 8-25°H, pH 8.0-9.5
Max. Size: 18″
Color Form: Brown, Beige
Diet: Carnivore
Compatibility: Single species tank or community
Origin: Africa; endemic to Lake Tanganyika
Family: Mastacembelidae
Lifespan: 15 years
Aquarist Experience Level: Intermediate/Advanced

Scopas Tang (Zebrasoma scopas)

Scopas Tang (Zebrasoma scopas) known to tropical fish keeping enthusiasts as the Brush Tail Tang, Two Tone Tang, or Brown Tang is found throughout the Indo Pacific and ranges from the coasts of East Africa to Japan, the Pitcairn Islands, Malaysia, Indonesia, Japan, Australia, Lord Howe Island and Rapa Iti.   Although several Brown Tangs were observed far outside their range near Fort Lauderdale, Florida, they were no doubt released aquarium specimens.

Adult Scopas Tangs are quite gregarious and can be found in pairs, singly, or in large schools on the exposed side of reefs in the coral rich lagoons of their range at depths to 200 feet.   Juvenile Scopas Tangs are much more solitary and prefer shallower waters where they swim among the corals grazing on filamentous algae, detritus, and small invertebrates.

Scopas Tang (Zebrasoma scopas)

The Scopas Tang has a deep, laterally compressed body with a protruding snout and specialized pharyngeal teeth that they use for feeding on filamentous algae.   They have a whitish tan colored head and a pale brown colored body that becomes a dark brownish black near the darker, nearly black tail and a white spine on the caudal peduncle.   Squiggly pale green to yellow longitudinal lines on the body begin as small dots at the head and continue through the posterior region into dots around the caudle pendacle.

Juvenile Brown Tangs are somewhat paler than adults, have thin yellowish white vertical lines that transverse the body, and have exaggerated dorsal and anal fins.

Scopas Tang coloration is highly variable.   Specimens can be solid black or solid yellow and incorporate various shades of gray, brown, yellow, and white in their body coloration.   Fiji colored Scopas are mostly yellow, dorsally, and brown, ventrally.

Adult males are generally larger than females.

The Scopas Tang is reef safe and can be housed in either a mature FOWLR or reef aquarium of at least 125 gallon capacity with a crushed coral or coralline sand substrate, good amounts of live rock arranged into caves, crevices, and overhangs, and plenty of free swimming space.   They will not bother corals and will voraciously eat any nuisance algae that inadvertently grows in the tank.

Brown tangs are one of the more peaceful species within its genus that can be kept with other tang species.   Other tankmates can include Flame Angelfish (Centropyge loricula), Royal Gramma (Gramma loreto), Firefish Goby (Nemateleotris spp.), Lawnmower Blenny (Salarias spp.), Blue Green Chromis (Chromis viridis), etc.

Although the Scopas Tang is tolerant of a wide range of water parameters; adequate water flow, good filtration, heavy protein skimming, and regular small water changes are recommended to maintain water quality.

The Scopas Tang is occasionally available to hobbyists through aquaculture, however, they have not been bred in an aquarium environment.

Although the Scopas Tang is primarily monogamous, they have been observed spawning in pairs and in small groups. The larger males rush up to the surface to spawn with the smaller females. The externally fertilized eggs are scattered into the water column where the planktonic larvae drift with the current for several weeks before settling to the bottom. The larvae feed on microalgae until their metamorphosis into juveniles.

Where their range overlaps, the Scopas Tang (Zebrasoma scopas) and Black Tang (Zebrasoma rostratum) are known to hybridize. The offspring have less elongated snouts, a bluish body color, slightly more yellow dorsal fins, and eyes that appear more orange.

In their natural habitat, Zebrasoma scopas feed mainly on filamentous algae. In an aquarium environment they will accept a variety of vegetable and meaty foods. In addition to the nuisance hair algae that they may consume in the tank; they should be offered plenty of seaweed, sheets of high quality marine algae, Spirulina, marine herbivore pellets, and occasionally frozen meaty foods like brine and Mysis shrimp.

It is important that plenty of fresh, frozen, or freeze dried marine based seaweed and algae is provided to strengthen their immune systems, reduce aggression, and improve their overall well being.

Dried Nori tied to a rock or clipped in a veggie clip should be presented on a daily basis or at least three times a week.   Sea Veggies, Seaweed Salad, and Ocean Nutrition are all ideal products that are convenient to use.

The Scopas Tang (Zebrasoma scopas) is readily available to tropical fish keeping enthusiasts from specialty fish shops and online from wholesalers, retailers, and trans shippers at the following approximate purchase sizes: Small: 1″ to 2″; Small/Medium: 2″ to 3″ Medium: 3″ to 4″; Medium/Large: 4″ to 5″; Large: 5″ to 6″; XLarge: 6″ or Higher.

Prices vary according to size and locale and range from $39.99 for small Indonesian and Philippines specimens to $149.99 for medium Fiji specimens.

Scopas Tang (Zebrasoma scopas)

Minimum Tank Size: 180 gallons
Aquarium Type: Reef or FOLR
Care Level: Moderate
Temperament: Peaceful to Semi-aggressive
Aquarium Hardiness: Very Hardy
Water Conditions: 74-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Maximum Size: 12″
Color Form: Black, Brown, Yellow
Diet: Omnivore
Compatibility: Reef or FOWLR
Origin: Indo Pacific
Family: Acanthuridae
Lifespan: 7 – 10 years
Aquarist Experience Level: Intermediate

Black Tang (Zebrasoma rostratum)

The Black Tang (Zebrasoma rostratum) known to tropical fish keeping enthusiasts as the Black Longnose Tang, Longnose Surgeonfish, Longnose Tang, and Longnose Sailfin Tang is an uncommon species found in the western central Pacific Ocean.

In the Eastern Pacific, the Black Tang is found in the Line, Marquesas, Society, Tuamoto, and Pitcairn Island groups and range from Tuvalu, east to Pitcairn, including all of French Polynesia, north to the Line Islands and south to Rapa Iti. Specimens have also been recorded off Oahu in Hawaii.

The Black Longnose Tang is an active but relatively solitary benthopelagic species that can be found on the coral rich seaward reefs and rocky outcroppings of their range at depths from 3 to over 200 feet. Although adults are occasionally found in relatively shallow water, they prefer grazing on the deeper seaward reefs among rocky outcroppings.

Juveniles are typically found at shallower depths to 70 feet where they spend their days foraging on small invertebrates and filamentous algae among rocky structure and coral formations.

Black Tang (Zebrasoma rostratum)

Juvenile Black Tangs are not totally black. They are gray towards the head and black on the posterior regions.   As they mature into adulthood, their laterally compressed body turns into a deep dark brown to jet black color with subtle golden hues on the outer margins of their dorsal and anal fins, blue pectoral fins, and a bright diamond shaped white patch around the spines on the caudal peduncle.

Males develop a patch of bristles directly in front of the spines and both sexes possess an elongated snout that distinguishes them from their cousin, the Scopas Tang.

Around Hawaii where their range overlaps, the Black Tang (Zebrasoma rostratum) and the Scopas Tang (Zebrasoma scopas) are known to hybridize. The offspring have less elongated snouts, a bluish body color, slightly more yellow dorsal fins and eyes that appear more orange.

The Black Longnose Tang is best housed in an aged FOWLR or reef aquarium of at least 180 gallon capacity with a crushed coral or sandy substrate, substantial amounts of mature live rock arranged into caves, crevices, and overhangs for them to hide among, and plenty of free swimming space.   The Black Tang is a peaceful fish that is perfectly suited for community tanks however they can become aggressive with other surgeonfish of their own genus.

In a FOWLR aquarium good tankmates include Clownfish, Dottybacks, Dartfish, Gobies, Blennies, Damselfish, and Anthias.   They will also get along with Purple Tangs (Zebrasoma xanthurum), Powder Blue Tangs (Acanthurus leucosternon), and dwarf angelfish like the Flame Angelfish (Centropyge loriculus) and Coral Beauty Angelfish (Centropyge bispinosa) when added to the tank last. Non Zebrasoma species should be avoided.

Although Black Tangs are well suited for large reef systems and will generally ignore invertebrates and corals, a hungry specimen may occasionally nip on clam mantles and LPS corals.

Like all tangs, Zebrasoma rostratum need plenty of swimming area and highly oxygenated water with plenty of water flow to thrive; so a wave maker powerhead, a strong protein skimmer, good filtration, and regular water changes are mandatory to maintain their immune systems and prevent illness. In their natural environment, cleaner wrasses (Labroides sp.) remove parasites from their bodies, so adding a couple to the tank should also be considered.

As of this date, Black Tangs have not been bred in an aquarium environment.

In their natural habitat, Black Long Nose Tangs feed on various macro and micro algae, detritus, and small invertebrates.   In an aquarium environment, tropical fish keeping enthusiasts should try to replicate their natural grazing behavior as closely as possible.

In addition to the live rock in the tank, they should be provided with plenty of seaweed, sheets of high quality marine algae, Spirulina, marine herbivore pellets, and occasionally some frozen meaty foods like brine shrimp and Mysis shrimp.

Although Black Tangs will eat meaty foods fed to the other fish in the aquarium, it is important that they are given plenty of fresh, frozen, or freeze dried marine based seaweed and algae to strengthen their immune systems, reduce aggression, and improve their overall well being.

Dried Nori tied to a rock or clipped in a veggie clip should be presented on a daily basis or at least three times a week.   Sea Veggies, Seaweed Salad, and Ocean Nutrition are all ideal products that are convenient to use.

Because of its limited range, the Black Tang (Zebrasoma rostratum) is somewhat rare in the aquarium trade and demands a higher price than other Zebrasoma species. They are available on a waiting list basis from specialty fish shops and online from wholesalers, retailers, and trans shippers at the following approximate purchase sizes: Small: 1-1/2″ to 2-1/4″; Small/Medium: 2-1/4″ to 3-1/4″; Medium: 3-1/4″ to 4-1/4″; Medium/Large: 4-1/4″ to 5-1/4″ Large: 5-1/4″ to 6-1/4″ XLarge: 6-1/4″ to 7-1/4″.

Prices vary according to size and range from $1699.99 to over $3379.99.

Black Tang (Zebrasoma rostratum)

Minimum Tank Size: 180 gallons
Aquarium Type: Reef or FOLR
Care Level: Moderate
Temperament: Peaceful to Semi-aggressive
Aquarium Hardiness: Very Hardy
Water Conditions: 74-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Maximum Size: 8.3″
Color Form: Black, Blue
Diet: Omnivore
Compatibility: Reef or FOWLR
Origin: Easterhn and western central Pacific Ocean
Family: Acanthuridae
Lifespan: 10 – 15 years
Aquarist Experience Level: Intermediate

Orangeshoulder Tang (Acanthurus olivaceus)

The Orangeshoulder Tang (Acanthurus olivaceus) known to tropical fish keeping enthusiasts as Orange Epaulette Surgeonfish, Orangespot Surgeonfish, Orangeband Surgeonfish, Olive Tang, Yellow Orange Tang, and Orangeshoulder Surgeonfish is found throughout tropical Indo-West Pacific waters.

The Orangeshoulder Tang ranges from Christmas Island and the Cocos Keeling Islands to southern Japan; Western, North, and Eastern Australia, Indonesia, Polynesia, the Phillippines, and Hawaii.

Adult Orangeshoulder Tangs are a solitary species that are occasionally seen in small schools along the outer reef slopes at depths from 30 to over 150 feet where they feed on detritus, filamentous algae, and the film of diatoms on the sea bed.   Adults frequently form schools in more exposed areas of the outer reef slopes where they can be seen grazing with parrotfish and other species of surgeonfish that have the same dietary needs.

Juvenile Acanthurus olivaceus are normally found in small groups around more sheltered structure in shallower water than adults.

The Orangeshoulder Tang is a deep bodied, laterally compressed oval species that can reach 14 inches in length.

Juvenile Orangeshoulder Tang (Acanthurus olivaceus)

Juvenile Orangeshoulder Tangs have a solid yellow body color with just the slightest hint of blue fringing on the anal and dorsal fins.

Orangeshoulder Tang (Acanthurus olivaceus)

Adult Orangeshoulder Tangs have a greyish to olive brown body with a sharp vertical line that separates the paler front half of the fish from the darker hind portion.   They have a distinctive orange or red bar surrounded by a purplish black margin immediately behind the top of the gill cover with blue and orange lines at the bases of the fins.   The blue highlighted dorsal and anal fins are long, low, and extend almost to the caudal peduncle.   The caudal fin is lyre shaped with points that grow longer as the fish mature. Like all surgeonfish, Acanthurus olivaceus posses a pair of scalpel like scales that project upward from the caudal peduncle.

Adult males develop a convex snout that clearly differentiates them from females.   Females grow much faster than males and are usually an inch or so larger than males as adults.   Males and females can change color from dark to pale almost instantaneously when disturbed.

Orangeshoulder Tangs are best housed in a FOWLR or reef aquarium of at least 180 gallon capacity with a crushed coral or sandy substrate, substantial amounts of mature live rock arranged into caves, crevices, and overhangs for them to hide among, and plenty of free swimming space.   They are peaceful fish that are perfect for community tanks but can get aggressive with other surgeonfish of their own genus.

In a FOWLR tank good tankmates include Clownfish, Dwarf angelfish, Dottybacks, Dartfish, Gobies like the Mandarin Goby, Blennies like the Lawnmower Blenny or the Bicolor Blenny, Dartfish, Damselfish, and Anthias.

Although Orangeshoulder Tangs are well suited for large reef systems and will generally ignore invertebrates and corals, a hungry specimen may occasionally nip on LPS corals or the slime that clams produce.

Like all tangs, Orange Epaulette Surgeonfish need a lot of swimming area and water turbulence to thrive, so a strong protein skimmer, good filtration, and regular small water changes are mandatory to prevent illness. In the wild cleaner wrasses (Labroides sp.) remove parasites from their bodies, so adding one or more to the tank should also be considered.

Orangeshoulder Tangs are egg scatterers that have never been bred in an aquarium environment. In the wild, females disperse their eggs into the water column near the surface where the males fertilize them as they drift toward the surface.

The Orangeshoulder Tang is an omnivore that requires plenty of marine algae and dried seaweed to strengthen their immune systems, reduce aggression, and improve their overall health. In their natural habitat they graze on detritus and algae growing on the seabed, as well as the film of diatoms and filamentous algae growing on the sand and on other substrates.

In an aquarium environment they should be offered Spirulina, frozen vegetables, herbivore flake foods, dried marine algae, and occasionally Mysis shrimp for protein. Dried nori tied to a rock or clipped on a veggie clip should also be provided at least 3 times per week.

Sea Veggies, Seaweed Salad, and Ocean Nutrition are all ideal products that are convenient to use.

Because the Orangeshoulder Tang (Acanthurus olivaceus) has not been bred in captivity, all specimens kept by tropical fish keeping enthusiasts are wild caught and are priced accordingly.

They are available from specialty fish shops and online from wholesalers, retailers, and trans shippers at the following approximate purchase sizes: Juvenile Small: 2″ to 3″; Changing: 3″ to 4″; Adult Small: 4″ to 5″; Medium: 5″ to 6 1/2″; Large: 6-1/2″ to 8″; XLarge: 8″ or Larger. Prices can range from $ 25.00 for juveniles to $ 579.00 for adults depending on the area of capture.

Orangeshoulder Tang (Acanthurus olivaceus)

Minimum Tank Size: 180 gallons
Aquarium Type: Reef or FOLR
Care Level: Moderate
Temperament: Semi Aggressive
Aquarium Hardiness: Very Hardy
Water Conditions: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Maximum Size: 14″
Color Form: Black, Blue, Yellow
Diet: Herbivore
Compatibility: Reef or FOWLR
Origin: Indo-Pacific, Red Sea, Africa, Hawaii, Australia
Family: Acanthuridae
Lifespan: 10 – 15 years (35 years in the wild)
Aquarist Experience Level: Intermediate

Two Spot Bristletooth Tang (Ctenochaetu binotatus)

The Two Spot Bristletooth Tang (Ctenochaetu binotatus) is widespread throughout the Indo-Pacific from the eastern African coast in the Indian Ocean between Kenya and Spdwama Bay in South Africa, all the way to the Andaman Sea.  In the Pacific it has been seen as far east as the Tuamotu Islands and Mangareva, and between southern Japan and New South Wales.

Two Spot Bristletooth Tang are a peaceful species that are usually encountered alone on the seaward coral reefs and deeper lagoons of their range feeding on detritus and single celled algae around corals and rock rubble at depths down to 200 feet.

Ctenochaetu binotatus feed on single celled algae such as the dinoflagellate Gambierdiscus toxicus by scooping up the film of detritus with its bristle like mouth.

The Two Spot Bristletooth Tang is one of the smallest tangs and is prized by tropical fish keeping enthusiasts for its disposition, personality, and beauty.

Two Spot Bristletooth Tang (Ctenochaetu binotatus)

Two Spot Bristletooth Tangs have a brown body color with blue eyes and pale spots along the head and chest. They have blue spots on their head, pale horizontal lines along the flanks, and two black spots at the base of the dorsal and anal fins that give them their common name. Adults develop a lunate caudal fin and display no distinguishing characteristics between males and females.

Like all tangs, Ctenochaetu binotatus have a sharp retractable spine on each side of the caudal peduncle that they use for defense.

The Two Spot Bristletooth Tang is best housed in a mature FOWLR or reef tank of at least 75 gallon capacity with a crushed coral or sandy substrate, substantial quantities of mature algae encrusted live rock arranged into crevices, caves, and overhangs for them to graze and hide among, plenty of free swimming space, and a moderate linear flow of water movement in at least one area of the tank.

The Two Spot Bristletooth Tang is considered reef safe and although they are aggressive towards other Tangs, they get along well with other peaceful tank mates like Clownfish, Green Chromis, Blennies, Royal Gramma, smaller Angelfish, Cardinalfish, etc.

They generally will not bother sessile invertebrates or corals in a reef tank, however they may nibble at stony corals if enough algae is not provided.

Like all tangs, Ctenochaetu binotatus are difficult to breed in an aquarium environment.

Like other members of the surgeonfish family, they are egg scatters that broadcast their spawn in groups. Visual sexing is next to impossible but if you plan to keep a breeding harem of Two Spot Bristletooth Tangs, you will need at least 6 to 10 juvenile individuals in an appropriately sized aquarium to develop and identify a breeding pair.

The Two Spot Bristletooth Tang is a herbivore that requires a steady diet of marine based algae and seaweed to remain healthy.   Although Tangs will eat meaty foods along with the other fish in the aquarium, it is important that they are provided plenty of marine based seaweed and algae to strengthen their immune system, reduce aggression, and improve their overall health.

Spirulina flakes, seaweed, and dried nori tied to a rock or clipped on a veggie clip should be provided at least 3 times per week. Sea Veggies, Seaweed Salad and Ocean Nutrition are all ideal products that are convenient to use.

The Two Spot Bristletooth Tang (Ctenochaetu binotatus) is a common species that is frequently available to tropical fish keeping enthusiasts from brick and mortar fish shops and online from specialty fish shops, wholesalers, retailers, and trans shippers at the following approximate purchase sizes: Small 1.5-2.25″; Medium 2.25-3.25″; Large 3.25-4.25″.

Specimens are commonly collected from the Philippines, Africa, and Indonesia at prices from $ 99.99 for Medium Philippines specimens to $ 199.99 for the same size Indonesian collected specimen.

Two Spot Bristletooth Tang (Ctenochaetu binotatus)

Minimum Tank Size: 75 gallons
Aquarium Type: Reef or FOLR
Care Level: Moderate
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-79° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Maximum Size: 8″
Color Form: Blue, Tan
Diet: Omnivore
Compatibility: Reef or FOWLR
Origin: Indo-Pacific, Africa, Phillipines, Africa
Family: Acanthuridae
Lifespan: 20+ years
Aquarist Experience Level: Intermediate