TankBud

Fathead minnow

Pimephales promelas

Also known as Rosy red minnow

FreshwaterFish

Fathead minnow (Pimephales promelas)
Dhester88 · CC BY-SA 4.0

Care at a glance

Temperature
50–72°F
10–22°C
pH
6.5–8.0
Adult size
3 in
7.5 cm
Minimum tank
20 gal
75 L
Temperament
Peaceful
Social behavior
Schooling
Swim level
Bottom
Difficulty
Easy
Breeding
Substrate spawner · Medium
Rarity
Common
Family
Cyprinidae
Origin
North America

Overview

The fathead minnow is a peaceful schooling fish for a cool, unheated tank. It is about as easygoing as fish get.

Did you know

Fathead minnows release an alarm substance from their skin when injured. Nearby fish smell it and immediately scatter or freeze. The warning system is so reliable that researchers use the fathead minnow as a standard test animal in water pollution studies.

Caring for the fathead minnow

Keep fathead minnows in a group, since they are peaceful schoolers. A tank of 20 gal (75 L) gives a small group plenty of room. A simple setup with some plants and a sandy or fine gravel bottom suits them. They mostly work the lower part of the tank.

Keep the water cool and unheated, at 50 to 72°F (10 to 22°C). They do poorly in warm tropical tanks over the long run. They accept a pH of 6.5 to 8.0. They eat flake, pellets and frozen or live foods without complaint.

Breeding males turn dark, grow a fleshy pad on the back and develop rows of bumps called breeding tubercles on the snout. The male guards eggs laid on the underside of a flat surface, which is unusual care for a minnow. Breeding them takes moderate effort.

Good to know

The fathead minnow is a small cyprinid in the family Cyprinidae. The orange and gold aquarium strain sold as the rosy red minnow is a color form of this same species.

In the wild

Fathead minnows are a hardy North American fish of ponds, ditches and slow streams. They often live in murky or low-oxygen water that defeats fussier species, and they tolerate a wide range of conditions.

Weekly picks

Tank mates

The fathead minnow is a peaceful, schooling species that keeps to the bottom. 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 fathead minnow need?

A fathead minnow needs at least 20 gal (75 L). It spends most of its time in the bottom.

What temperature and pH does a fathead minnow need?

A fathead minnow is comfortable at 50–72°F (10–22°C) with a pH of 6.5–8.0.

What does a fathead minnow eat?

A fathead minnow eats flake, pellets and frozen or live foods without complaint.

How big does a fathead minnow get?

An adult fathead minnow reaches about 3 in (7.5 cm).

Does a fathead minnow need a group?

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

How can you tell a male fathead minnow from a female?

Males in breeding condition turn dark and grow a fleshy pad on the back. They also develop rows of bumps, called breeding tubercles, on the snout.

How does a fathead minnow breed?

Fathead minnows lay their eggs on the underside of a flat surface, and the male guards them. That is unusual care for a minnow, and breeding them takes moderate effort.

Related species