What Fish Are Compatible With Crayfish?

Crayfish are omnivorous, meaning they eat meat and vegetables. Fish are a dietary staple, and if you put fish in a tank with a crayfish, the crayfish will try to eat the fish. This makes compatibility with other fish difficult. When you keep a crayfish, learn about the types of foods that crayfish are most attracted to and which types of fish they don't much care for.

  1. Type of Fish

    • No fish is truly compatible with a crayfish. While other fish in a tank may mind their own business, it is within the crayfish's nature to hunt them. From goldfish to shrimp, the crayfish does not differentiate. Rather, the crayfish will see the other type of fish as food.

    Size of Fish

    • If you are going to put another fish in a tank with a crayfish, select a fish that is larger than the crayfish in size. A larger fish can defend itself against the crayfish more easily than a small one. And it's possible that the crayfish will not even attempt to attack it because it sees the large fish as a threat. Loaches, Koi, Rainbowfish and aquarium sharks may be suitable companions for a crayfish due to their size.

    Schools of Fish

    • If you keep a school of fish -- even small fish, like goldfish -- in a tank with a crayfish, this, too, is an environmental factor that affects the compatibility. A crayfish may leave a school of fish alone, as opposed to a single fish that can easily be eaten, thereby enhancing the compatibility. However, it's also possible that the crayfish may be hunted and eaten by the school of fish, if the fish are predatory and the crayfish does not do an effective job of hiding from them.

    Habitat Consideration

    • Another compatibility issue involves the actual habitat. Crayfish will become more predatory and even cannibalistic if they are not provided with enough space, or if they feel too crowded in their environment. If you want to keep a captive crayfish happy, give it plenty of room by providing a large tank, and make sure you keep feeding it so that it does not feel tempted to prey on the other fish in the tank.