Tag Archive | "Silver Dollar (Metynnis hypsauchen)"

Silver Dollar (Metynnis hypsauchen)

Silver Dollar (Metynnis hypsauchen)

Silver Dollar (Metynnis hypsauchen) is a generic name tagged to a number of tropical species in the Characidae (now Serrasalmidae) family which are closely related to the South American Pacu and Piranha; all of which are popular with tropical fish keeping enthusiasts.

The common Silver Dollar (Metynnis hypsauchen) is distributed throughout parts of Brazil, Guyana, Bolivia, Peru, in both the Amazon and Rio Paraguay drainages, and some of the northern rivers in the Guyana Shield. All species of Silver Dollars live in tropical climates and in highly vegetated, weedy rivers and prefer low light conditions.

The common Silver Dollar (Metynnis hypsauchen) is a peaceful, nervous, schooling species that inhabits the densely vegetated river tributaries of their range.   They are primarily vegetarians and zealous plant eaters, but they are also opportunistic feeders and will readily eat worms, small insects, and small fish.   In an aquarium environment, they can quickly decimate a well planted tank

Although they are listed as a semi aggressive species, they are more like Pacu in temperament.   As juveniles, they can be housed in a peaceful community tank  setting with fish of the same size.   However, if they can get a fish into their mouths, they will eat it.   Once full grown, they can be housed with larger catfish, other silver dollar species, Oscars, etc.

Silver Dollar (Metynnis hypsauchen)

Silver Dollar (Metynnis hypsauchen)

Metynnis hypsauchen is round and silvery; just as it’s name implies.   It’s body is laterally compressed, almost round in appearance and colored silver with a hint of green and blue.

The anal fin of the male is edged in red which becomes more pronounced during breeding.   Some species have a series of small dots on their sides.

It’s close relative, Metynnis argenteus, is also known to tropical fish keeping enthusiasts as the Silver Dollar.   This species looks identical to Metynnis hypsauchen except for the black shoulder patch that they possess slightly above and behind each eye.

Because Silver Dollars are a schooling fish that grow quite large, they are best housed in at least a 55 gallon or larger aquarium with a dark gravel substrate, that is densely planted with hardy plants like Java Fern, Hornwort, etc., some pieces of driftwood for them to hide among, and some floating plants to diffuse overhead lighting.   A shallow, peat filtered tank is recommended to replicate their water parameters.

Being a schooling species, they do best when kept together with at least 5 or 6 other individuals when housed in a single species biotope setup.   In a peaceful community tank with other larger fish,

Silver Dollar (Metynnis hypsauchen)

Silver Dollar (Metynnis hypsauchen)

at least 3 or 4 should be kept together with plenty of hiding places, to keep them from becoming overly skittish and reclusive..

The best way to breed Metynnis hypsauchen is to purchase 6 or more juveniles and raise them together in a 75 gallon or larger tank to adulthood.   Eventually a pair or two will develop.   The breeding tank should be heavily planted with fine leaved plants and the lighting should be subdued.   The water should be kept at a temperature of 80 to 82 degrees F, the pH slightly acidic, and the hardness at 8 dgH or less. .

Providing a warmer water change will often trigger spawning.

When ready to spawn, the male’s colors around the anal, caudal, and dorsal fins will become darker, and the red around the chest area will intensify.   The male will begin to court the females by chasing them around the tank and shimmying to entice them.   When ready to breed, the female will release up to 2,000 eggs which, after being fertilized by the male, will drop to the bottom of the tank.   The eggs will hatch out in about 3 days at a temperature of 82 degrees F.

At this stage, even though the parents will unlikely eat their eggs or fry, it is better to remove them to another tank.   After a week or so, the fry will absorb their yolk sacs and become free swimming.   They can initially be fed infusoria until they are able to consume freshly hatched brine shrimp, finely crushed spirulina, and commercial prepared fry foods.   Egg mortality can be quite high, but a layer of Indian Almond Leaves on the bottom of the breeding tank can minimize losses.

Silver Dollars require a large amount of vegetable matter in their diet.   They can be fed commercial algae wafers, spirulina flakes, and regular offerings of cucumbers, peas, zuchinni, etc.   They will also eagerly accept occasional offerings of fresh, frozen, or freeze dried bloodworms, earthworms, ghost shrimp, and brine shrimp.

Both Metynnis hypsauchen and Metynnis argenteus are readily available in tropical fish keeping shops and online at reasonable prices.   They are usually sold as juveniles when they are 1 3/4″ in size or larger.

Silver Dollar (Metynnis hypsauchen)

Silver Dollar (Metynnis hypsauchen)








Minimum Tank Size: 55 gallons
Care Level: Moderate
Temperament: Peaceful
Aquarium Hardiness: Moderately Hardy
Water Conditions: 75-82 °F°, <10dgH, pH 6.0-7.0
Max. Size: 6″
Color Form: Silver
Diet: Omnivorous (primarily Herbivorous)
Compatibility: Aggressive to small fish
Origin: Brazil, Guyana, Boliva, Peru
Family: Characidae (Serrasalmidae)
Life Span: 15 years or more
Aquarist Experience Level: Intermediate

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