The Crayfish Copulation Process

Crayfish are crustaceans that live in freshwater. They look like small lobsters and are often seen in streams and creeks with fresh running water. Crayfish prefer dark and cool places, most often hiding under rocks and other shelter during the day. Like most animals, crayfish reproduce sexually.

  1. Identification

    • While crayfish are either male or female, some crayfish have both male and female genital openings. However, these crayfish are generally classified as male. Male crayfish have larger pincers than their female counterparts, and tails that are more narrow. The male crayfish have two pairs of leg-like appendages called swimmeretes under the tail, while the females have space between their tail to hold the eggs.

    Mating

    • Most often in the spring, the male and female crayfish send signals to one another that indicate it's time to breed. During copulation, a male crayfish starts the process by coming up to the female from behind. He then hits her with his antennae to indicate his intentions. Then, the male crayfish flips the female over. During the copulation process, the male crayfish deposits a sperm packet that looks like a tiny cotton ball under the female crayfish's belly. Once it is in place, the female will curl her tail and push down the eggs she has produced so they travel through the sperm and then attach to the swimmeretes under her tail. Females typically lay about 200 eggs.

    Incubation

    • The eggs will remain under the female's tail for about four weeks as they gestate. The gestation period is even longer for crayfish species that live in colder environments. When the baby crayfish are born, they emerge perfectly formed and ready to eat. They remain under the female's tail for the first days of life for protection against predators. While under the tail, these baby crayfish will eat tiny particles of food in the water that float by.

    Pseudo-Sex

    • In 2006, scientists discovered that male crayfish engage in fake sex to prove dominance. The process of "pseudocopulation" creates hierarchies among the male crayfish and helps maintain peace in their environment. Without this process, where the dominant male flips over the subordinate male, it is likely more death in the male population will occur. Males that do not take part in pseudocopulation fight to the death. The process creates a pecking order among the crayfish and cuts down on aggression.