Life Cycle of a Crawfish

The crawfish, a decapod (ten-limbed) crustacean, lives its life predominately in fresh water regions such as rivers, streams and lakes. They only occasionally venture onto land. Their overall appearance mimics that of a small lobster. Crawfish measure 2 to 6 inches in length, depending on the species. Currently, around 150 species of crawfish inhabit North America. Worldwide, 540 species exist. Their average lifespan ranges from only 2 to 4 years.

  1. Spawning

    • In temperate regions spawning occurs year round, but the normal time of year is late spring to early summer. Many females will breed more then once per year. Within open water mating occurs between the female and male crawfish. The male deposits his semen into the female's annulus ventralis (receptacle). The female will continue to mate with numerous males of her choice before burrowing in to a burrow she creates from mud to lay her eggs. The eggs remain attached to the female's underbelly once laid.

    Burrow

    • The burrow that the female retreats to is normally located in an area that will maintain water even during a drought. She plugs the entrance to the burrow using a plug of soil. The female requires water within her burrow when expelling her eggs and when they attach to her abdomen. The female will have between 200 to 500 eggs depending upon her health and size, according to the University of Kentucky.

    Incubation and Hatching

    • When the eggs are approximately three weeks old they will begin to hatch if the temperature has been maintained at around 74 degrees F. After the eggs hatch the baby crawfish will continue to cling to their mother's underbelly until they go through two molts, which occurs over the course of several weeks. Normally, the female crawfish remains a good mother to her hatchling crawfish, but if very little food exists then she will resort to cannibalism. After the eggs hatch the female leaves the burrow with her brood firmly attached to her underbelly in search of food. Unfortunately, during the search for food the young will often become dislodged from her and perish.

    Molting

    • As the young crawfish grow they must shed their exoskeleton. Over the course of one year the crawfish will molt twice when attached to its mother and then nine more times before it reaches sexual maturity. Many variations affect when the molting will occur for the crawfish. It is largely dependent on abundant food and adequate temperatures. Once sexual maturity is reached the crawfish no longer sheds its exoskeleton.

    Maturity

    • Once mature, a male crawfish will develop a darker color than the female. He will also grow large hooks at the end of this third and fourth legs. Males have a very aggressive nature when it comes to hunting and defense, so the hooks are used as a weapon. Two adults who meet up rear onto their hind legs and eject urine into each others faces to show dominance, status and general health to each other. Fighting proceeds the behavior and tends to be quite brutal. Many crawfish males will loose limbs in combat with each other. Lost limbs will regenerate over time if the crawfish lives through the fight.