TankBud

Northern studfish

Fundulus catenatus

FreshwaterFish

Northern studfish (Fundulus catenatus)
Noel Burkhead, USGS · Public domain

Care at a glance

Temperature
59–77°F
15–25°C
pH
6.5–8.0
Adult size
5.9 in
15 cm
Minimum tank
37 gal
140 L
Temperament
Mostly peaceful
Social behavior
Social
Tankmates
With caution
Swim level
Middle
Difficulty
Difficult
Breeding
No record
Rarity
Very rare
Family
Fundulidae
Origin
United States

Overview

The northern studfish is a large, active topminnow that does best as a group in a long, roomy tank. It is a fish for experienced keepers.

Did you know

Northern studfish males in courting color compete with each other for the best patches of open gravel at the shallow edges of streams.

Caring for the northern studfish

Give northern studfish a tank of at least 37 gal (140 L), since adults reach a good size. Leave open swimming room over a sand or fine gravel bottom. They swim through the middle and upper water.

They like clean, well oxygenated conditions with some current. Keep the water cool to moderate, at 59 to 77°F (15 to 25°C), with a near-neutral to slightly alkaline pH of 6.5 to 8.0. Steady water movement keeps them in good condition.

Feed generously on live and frozen foods such as bloodworms, blackworms, crickets and brine shrimp. They accept some flake and pellet as well. Choose tank mates with caution.

Males display and spar, so give them space and line-of-sight breaks rather than a cramped tank. Unlike most topminnows, which lay their eggs on plants, the northern studfish spawns over clean gravel with no parental care. Its aquarium breeding is little recorded, partly because of the space a group of these big, lively fish needs.

Good to know

The northern studfish belongs to the topminnow family Fundulidae and is one of its larger members. Breeding males are boldly marked with blue bodies and red-brown spotting.

In the wild

Northern studfish live in clear, permanently flowing upland streams in the central United States. They keep to shallow margins over clean sand, gravel and rock, where the water is cool and well oxygenated for much of the year.

Common questions

What size tank does a northern studfish need?

A northern studfish needs at least 37 gal (140 L). It spends most of its time in the middle.

What temperature and pH does a northern studfish need?

A northern studfish is comfortable at 59–77°F (15–25°C) with a pH of 6.5–8.0.

What does a northern studfish eat?

A northern studfish eats live and frozen foods such as bloodworms, blackworms, crickets and brine shrimp. Feed it generously, and it accepts some flake and pellet as well.

How big does a northern studfish get?

An adult northern studfish reaches about 5.9 in (15 cm).

How does a northern studfish breed?

Northern studfish spawn over clean gravel rather than on plants, unlike most topminnows, and give no parental care. Their aquarium breeding is little recorded, partly because a group needs so much space.

Related species