The Functions of Crayfish Appendages

You've seen a crayfish's numerous antennae, spindly legs and lobster-like claws, whether observing them in the water or boiled and ready to be eaten, but do you know why so many legs and antennae are necessary? All of a crayfish's appendages have a specific use, even those tiny leg-like things underneath its tail.

  1. Antennae

    • Crawfish antennae are comparatively very long.

      You would think antennae aren't really something that needs to be explained. However, when a creature has four of them, rather than the two other creatures with antennae have, some explanation is required.

      Crayfish have two long antennae and two small antennules, both at the front of its mouth. The two long antennae are used for touch and taste and the two small antennules are for maintaining balance.

    Legs

    • Crayfish appear to have many more legs than they actually have.

      At first glance, it looks like a crayfish has legs all the way up and down its body and tail. However, the small appendages underneath its tail are called swimmerettes. They function, not surprisingly, as swimming appendages, for support as the crayfish walks about and in the reproduction process. Males use the first swimmerette to transfer sperm, and the females use their second through fifth swimmerettes to hold eggs onto the underside of their tails.

      A crayfish's actual legs are used only for walking. The legs are the eight appendages underneath the cephalothorax -- the section of the crayfish that isn't its tail.

    Claws

    • A crayfish's claws are often proportionally much larger than its other appendages.

      The large claws on the front of a crayfish are for capturing and grasping food. A crayfish also uses its claws to defend itself against other crayfish and sea creatures, as well as for walking.

    Mouth

    • A crayfish's mouth appendages are intricate.

      Look at the mouth of a crayfish and you will see an intricate set of appendages. The three sets that are used for feeding itself are called the maxillipeds. The three sets of maxillipeds differ in size and appearance, but all are for touching, tasting and moving food into its mouth.