Silver Dollar Identification Guide

Key identification features

• Round to oval, strongly laterally compressed body resembling a large coin, growing to about 6 inches (15 cm) or more
• Uniform bright silver coloring, sometimes with a faint yellow or olive tinge on the back
• Small adipose fin and a short, saw-edged keel of scutes running along the belly
• Deeply forked, symmetrical tail fin
• Some species show faint dark spots or reddish tints on the fins as adults

Common look-alikes

• Pacu: much larger and heavier-bodied at maturity, with a blunter head and flattened, molar-like teeth versus the silver dollar's smaller, more delicate mouth.
• Piranha: similar disc shape and silvery color but has a more pronounced underbite and a single row of sharp, triangular teeth visible when the mouth is closed.
• Diamond tetra: far smaller, with iridescent scale flecks rather than the uniform flat-silver, coin-like body of a silver dollar.

Where you'll see one

Native to slow, densely vegetated tributaries and flooded forest habitats of the Amazon and Paraguay river basins in South America, often schooling in open water.