TankBud

Plain metynnis

Metynnis hypsauchen

Also known as Silver dollar

FreshwaterFish

Plain metynnis (Metynnis hypsauchen)
Sesamehoneytart · CC BY-SA 4.0

Care at a glance

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

Overview

The plain metynnis is a large, mostly peaceful schooling fish for a big tank with open water. It suits a keeper with a little experience.

Did you know

The plain metynnis has a flat, silvery, disc-shaped body that acts like a mirror and scatters light. That breaks up its outline in open water, so predators have a harder time picking it out of a moving school.

Caring for the plain metynnis

Keep the plain metynnis in a group of at least five. Its size and activity mean it needs a big tank, at least 70 gal (265 L), with open swimming room.

Keep the water soft to neutral and warm, at 75 to 82°F (24 to 28°C) and a pH of 6.0 to 7.5. Feed an almost entirely plant-based diet of spirulina, vegetable flakes and fresh greens like spinach or lettuce. It will eat live plants, so plan around that.

The plain metynnis swims in the middle and upper water and is mostly peaceful. It can be nervous and skittish in small groups. It is an egg scatterer, and breeding it at home is difficult.

Good to know

Metynnis hypsauchen belongs to the family Characidae and is a close relative of pacus and piranhas. The very similar Metynnis argenteus shares its common name, silver dollar.

In the wild

The plain metynnis comes from the Amazon basin across Guyana, Brazil, Peru and Bolivia. It lives in slow, warm waters with plenty of plants and soft bottoms. The water there is slightly acidic, with lots of organic matter.

Weekly picks

Tank mates

The plain metynnis 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 plain metynnis need?

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

What temperature and pH does a plain metynnis need?

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

What does a plain metynnis eat?

A plain metynnis eats an almost entirely plant-based diet of spirulina, vegetable flakes and fresh greens such as spinach or lettuce.

How big does a plain metynnis get?

An adult plain metynnis reaches about 5.5 in (14 cm).

Does a plain metynnis need a group?

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

How does a plain metynnis breed?

The plain metynnis is an egg scatterer, and breeding it at home is difficult.

Related species