Fish
Silver Dollar
Metynnis argenteusAlso known as Silver Dollar Fish
Silver dollars glide through slow-moving river margins and flooded forests in synchronized, shimmering schools. Despite their close relation to sharp-toothed piranhas, their flattened, disc-shaped bodies house specialized blunt teeth adapted for grinding fibrous vegetation, fallen seeds, and river weeds. During high-water seasons, they disperse widely into inundated floodplains to forage on drifting plant debris and disperse seeds across the river basin.
FreshwaterSchoolingHerbivorous
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Diet & preySubmerged aquatic plants, Fallen river seeds, Filamentous algae
Predators
- Peacock bass
- Black caiman
- Neotropical cormorant
ThreatsDam construction, habitat alteration from deforestation, and aquatic pollution
HabitatsSlow-moving rivers, tributaries, and seasonally flooded forest basins with dense vegetation
Life span8–12 years
Classification
- OrderCharaciformes
- FamilySerrasalmidae
- GenusMetynnis
- SpeciesMetynnis argenteus
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Safe to observe at a normal distance.
Responsible observation
- Field Observation: Look for reflective flashes near sunny river edges choked with overhanging brush.
- Aquarium Care: House in schools of five or more in spacious tanks with durable, non-edible decorations.
Close Relative (c) Sesamehoneytart, some rights reserved (CC BY-SA) · cc-by-sa
Same Family (c) Marco Verch, some rights reserved (CC BY) · cc-by
Same Family (c) Brian Gratwicke, some rights reserved (CC BY) · cc-by
Image unavailableSame Family
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