- Scientific Name: Metynnis argenteus
- Family: Serrasalmidae
- Size: 5 to 8 inches
- Temperature: 75 to 82 degrees Fahrenheit
- Alkalinity: Undemanding
- Origin: South America
The silver dollar is a peaceful, schooling fish that can be kept in groups of three to six with most other community tank species of similar size. It should be housed in a medium to large tank with subdued lighting provided by floating plants (live or artificial) — which it may nibble on — and adequate hiding places in the form of rocks, flowerpots and driftwood.
The silver dollar is a herbivore that requires a diet high in vegetable matter, including any of the commercial Spirulina- and vegetable-based frozen, freeze-dried and flake foods. It will also accept small live foods, such as brine shrimp, bloodworms and glass worms. Supplement its diet with parboiled peas, zucchini and romaine lettuce.
Breeding this species has been successful in the home aquarium given the appropriate conditions. Although the male tend to have a longer anal fin that is tinged in red, to ensure successful pairing it is best to purchase four to six individuals and let them pair up.
The female will lay eggs among the floating plants. The eggs will immediately drop to the bottom, but will not be eaten. The eggs hatch after three days and the fry will become free-swimming within a week, attaching themselves to the tank glass where they will eat small plankton.