Green Tiger / Zebra Silver Dollar (Metynnis sp)

Green Tiger / Zebra Silver Dollar — Metynnis sp.
The moving wall of muscle

The Green Tiger Silver Dollar is what turns a tank into a living ecosystem. Instead of a single centerpiece fish, these South American characins create motion — a synchronized school that never stops moving. Vertical striping across a reflective silver body gives them the “zebra” appearance, while a subtle green metallic wash appears under strong lighting and dark backgrounds, flashing every time the group turns together.

Native to the flooded forests and river channels of the Amazon basin, Silver Dollars evolved to survive among predators. Their defense isn’t aggression — it’s numbers, speed, and awareness. When kept properly in groups, they move as one organism, reacting instantly to light, shadows, and feeding time. Few freshwater fish create the same natural river effect inside a large aquarium.

Reaching 6–8 inches, they grow into powerful swimmers and excellent companions for monster fish. Arowana, rays, large catfish, datnoids, and big cichlids all benefit from their presence — they act as dither fish, bringing confidence to shy predators and adding constant activity to otherwise slow tanks.

Despite their piranha-like appearance, they are primarily herbivores/omnivores and will eagerly graze greens, pellets, and fruit. Because of this, live plants rarely survive long — but that’s part of their authenticity. In nature, they help shape the environment they live in.

Hardy, social, and always alert, the Green Tiger Silver Dollar fills negative space in large aquariums better than almost any species.