TankBud

Silver dollar

Metynnis argenteus

FreshwaterFish

Silver dollar (Metynnis argenteus)
Greg Hume · CC BY-SA 4.0

Care at a glance

Temperature
75–82°F
24–28°C
pH
6.0–7.5
Adult size
5.9 in
15 cm
Minimum tank
70 gal
265 L
Temperament
Mostly peaceful
Social behavior
Schooling
Swim level
Middle
Diet
Omnivore
Difficulty
Medium
Breeding
Egg scatterer · Hard
Rarity
Rare
Family
Characidae
Origin
Brazil

Overview

The silver dollar is a large, active schooling fish for a big community tank, and a step up from the easiest fish.

Did you know

The silver dollar's grazing helps keep aquatic vegetation in check in the wild, and it moves nutrients through the system.

Caring for the silver dollar

Keep silver dollars in a school of five or more, in a large tank of at least 70 gal (265 L). A lone fish stays stressed and hidden. Open mid-water space matters more than heavy decor, so keep any planting to the edges.

They prefer soft to neutral, warm water, at 75 to 82°F (24 to 28°C) and a pH of 6.0 to 7.5. Feed mainly greens, such as vegetable flakes, spirulina and fresh spinach or lettuce, with protein foods only occasionally. Silver dollars are heavy plant eaters, and aquarists treat almost any live planting as temporary. Use tough plant species, or expect them to be eaten.

They are active mid and upper swimmers, and mostly peaceful with fish too big to swallow. They scatter their eggs and do not guard them, and home breeding is hard.

Good to know

Metynnis argenteus is a characin in the family Characidae, with a tall, round, silver body that gives it its name. The closely related Metynnis hypsauchen is often sold under the same name and looks nearly identical.

In the wild

The silver dollar comes from rivers and streams in Brazil's Amazon basin. The water there is warm, soft and slightly acidic, shaded by overhanging plants.

Weekly picks

Tank mates

The silver dollar is a mostly peaceful, schooling species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a silver dollar need?

A silver dollar needs at least 70 gal (265 L). It spends most of its time in the middle.

What temperature and pH does a silver dollar need?

A silver dollar is comfortable at 75–82°F (24–28°C) with a pH of 6.0–7.5.

What does a silver dollar eat?

A silver dollar eats mainly greens, such as vegetable flakes, spirulina and fresh spinach or lettuce. Give it protein foods only occasionally.

How big does a silver dollar get?

An adult silver dollar reaches about 5.9 in (15 cm).

Does a silver dollar need a group?

Yes. A silver dollar is a schooling species and should be kept in a group, not singly.

How does a silver dollar breed?

Silver dollars scatter their eggs and do not guard them. Home breeding is hard.

Related species