TankBud

Crucian carp

Carassius carassius

Also known as Crucian, European crucian carp

FreshwaterFish

Crucian carp (Carassius carassius)
Viridiflavus · CC BY-SA 3.0

Care at a glance

Temperature
39–75°F
4–24°C
pH
6.5–8.0
Adult size
11.8 in
30 cm
Minimum tank
119 gal
450 L
Temperament
Peaceful
Social behavior
Social
Tankmates
With caution
Swim level
Bottom
Diet
Omnivore
Difficulty
Easy
Breeding
Medium
Rarity
Common
Family
Cyprinidae
Origin
Native to ponds, lakes, and slow rivers across Europe and western Asia.

Overview

The crucian carp is a peaceful, cool-water fish for a pond or a very large tank. It is easy to keep.

Did you know

The crucian carp is one of the toughest of all freshwater fish, able to spend a whole winter sealed under ice in oxygen-starved water. It survives months of near-zero oxygen by switching to an unusual metabolism that turns waste lactic acid into alcohol. It releases the alcohol through its gills instead of suffocating.

Caring for the crucian carp

Crucian carp need a lot of space, so plan on at least 119 gal (450 L), with strong filtration. They spend most of their time near the bottom.

They are a temperate species rather than a tropical aquarium fish. Keep them in cool water at 39 to 75°F (4 to 24°C), with a pH of 6.5 to 8.0. They need no heating in most climates. Feed a varied omnivore diet of sinking pellets, plant matter and frozen or live foods such as bloodworm.

Crucian carp are peaceful and social, and they are fine alone or in a group. Choose their company with some care, though goldfish and other cool-water pond fish mix well with them. Breeding them is moderately difficult.

Good to know

The crucian carp, Carassius carassius, belongs to the family Cyprinidae and is a close relative of the goldfish, Carassius auratus. The two species can hybridize. It commonly reaches 15 to 25 cm and can grow larger in a big pond. It is also called the crucian or the European crucian carp.

In the wild

The crucian carp is a hardy, deep-bodied fish from still and slow waters across Europe and western Asia. It lives among thick plants in ponds, lakes and backwaters, rooting through soft substrate for food.

Common questions

What size tank does a crucian carp need?

A crucian carp needs at least 119 gal (450 L). It spends most of its time in the bottom.

What temperature and pH does a crucian carp need?

A crucian carp is comfortable at 39–75°F (4–24°C) with a pH of 6.5–8.0.

What does a crucian carp eat?

A crucian carp eats a varied omnivore diet. Feed it sinking pellets and plant matter, plus frozen or live foods such as bloodworm.

How big does a crucian carp get?

An adult crucian carp reaches about 11.8 in (30 cm).

Related species