Metynnis hypsauchen


Metynnis maculatus


Metynnis argenteus, Metynnis hypsauchen, Metynnis maculatus



    One of my favorite fish. The Silver Dollar is a peaceful schooling species with a great personality. One word of caution they love greens and will completely defoliate a fish tank in no time at all. They should have some short of vegetable supplement in their diet. There can be some species confusion in the pet stores and when young they can be difficult to iodentify. They have the same basic needs.

Quick stats:


Listed tank sizes are the minimum
Size: Up to 8″ (20cm)
Tank: 48 inches
Strata: Middle
PH: 6.0 to 7.5
Hardness: Soft to medium. dH range: 4.0 – 18.0
Temperature: 75°F to 84°F (24-29°C)



Order: Cypriniformes
Suborder: Characoidei
Super-Family: Characidoidea
Family: Serrasalmidae
Genera: Metynnis

Common name

    Silver dollar, Schreitmullers’ Metynnis


    Widely distributed throughout South America, from Guyana to Paraguay, including the Amazon river basin.

General Body Form

    Basically circular in shape, as long as tall, with very marked lateral compression. The front on profile of the back and stomach are not uniformly convex (out ) , but rather curve in at the Dorsal and Anal fin level. Like most members of the family (Piranha included!) they have tiny scales with small mouths and enlarged lips. The Caudal fin is slightly indented, the Adipose fin is long and short and in mature males the front part of the anal fin is crescent shaped. They can reach a size of five and one half inches, with the males smaller than the females.


    The entire body is basically a strong Silver/Gray, with a high iridescence, which is highlighted when the fish are in a large school. The back is slightly darker being Greenish/Gray or Greenish/Blue in color. The Anal fin has a pale tinge of Silver color in the front that fades toward the back. The Dorsal fin is clear with a series of small dark spots. In well cared for males, the Caudal fin and the Gill cover have a Reddish border. A narrow, dark vertical band runs through each eye. As with most fish there are color variations.


    Shallow areas of their home range that are heavily vegetated


    The Silver Dollars require a large tank, a standard 55 or 40 gallon would be fine. The tank should have no live plants as this species is mainly vegetarian in habit. The substrate should be dark in color with subdued lighting. They are schooling fish and will always be shy and skittish in a small tank, so give them as much room as possible. The diet should primarily include plant material, particularly Romaine Lettuce, along with the various live foods. Water quality is not critical and the temperature should be kept in the upper Seventies to low Eighties.


    In nature these fish spawn in shallow, sun drenched flooded areas of rivers. In the home aquarium they have been breed in clear aged water with a temperature between 81 and 90f. The eggs hatch in about four days and are free swimming a week later. If well fed they will grow very quickly.




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