Life Characteristics of Crayfish

Also called crawfish or crawdad, crayfish include numerous crustaceans belonging to the phylum Arthropoda. Crayfish are distinguished from other arthropods by their segmented body consisting of three parts: the head, the thorax section including the legs and the abdomen or tail section. Like other arthropods, crayfish have a hardened outer shell which serves as their skeletal system.

  1. Habitat

    • Freshwater streams, rivers, lakes, brooks, dams and swamps are habitats of crayfish. However, some species live in saltwater. They live in sheltered places like logs, rocks and debris where they can conceal themselves from predators. They are nocturnal animals. All crayfish have the ability to burrow, with some living in burrows several feet long. Their burrows usually have a mud chimney at the entrance, the chimneys themselves ranging from between an inch to over a foot high.

    Feeding Habits

    • Crayfish are bottom-feeders, spending much of their time foraging on the river bed for leaves, water plants and decaying roots. Although crayfish are principally vegetarian, they are also considered to be "opportunistic omnivores" which means that they will eat anything, and will feed on other animals like worms, tadpoles, snails and insect larvae if they happen to come across them.

    Molting

    • Like all arthropods, crayfish shed their exoskeleton in order to grow. Molting occurs every few weeks to annually, depending on the age and size of the animal, with larger, more mature crayfish shedding less often. Leading up to molting day, the crayfish reduces activity and feeding, laying virtually motionless. To shed their shell, the crayfish splits its tail along the back and flicks off the old shell, then removes its head and claws. They then remain in hiding until their new shell has fully hardened.

    Reproduction

    • The lifespan of a crayfish ranges from 1 to 20 years and sexual maturity ranges from a few months to several years depending on the species. Mating generally takes place in late spring to early summer. The female stores the male's sperm in a receptacle on her underside, then builds a burrow in which to spawn. The eggs attached to the female's abdomen hatch in 5 to 8 weeks and the hatchlings remain attached to their mother for several weeks more.