Louisiana Crawfish Species

Crawfish are freshwater crustaceans, looking like miniature lobsters. They are omnivores, and eat just about anything that stays still long enough for them to take a bite. Some crayfish live in the water all the time, while others build burrows on the banks of streams that look like little chimneys sticking out of the mud. Almost all crawfish are nocturnal, but if you turn over rocks in a stream you may find some and watch them swim away backwards, using their tail for propulsion.

  1. Louisiana Crawfish Species

    • Crawfish are a traditional Louisiana delicacy.

      There are 38 known crawfish species in Louisiana, and two of them are farmed commercially. Several of the species are in conservation status, as their exact range and numbers are not known. Most of the species are small, brownish creatures meant to blend with the mud they live in, but a few specimens are worthy of mention. The cajun dwarf crawfish is a tiny, pure white crawfish that ranges through several states. The devil crawfish is so named for the red tips of its claws. The painted devil crayfish is a multicolored crustacean, sporting blues, greens, and touches of red across its shell.

    Commercial Crawfish Species

    • Farming crawfish is big business in Louisiana. The two species used in farming are Procambarus clarkii (the red swamp crawfish) and Procabarus zongulus (the White River crawfish). Mature red swamp crawfish are bright red, as their name suggests. They are more aggressive than the White River crawfish, and make up most of the annual catch in Louisiana. They can spawn year round, while the White Rivers spawn only once a year. Both species live for only two years, starting their life cycle as eggs carried under their mother's tail. Even after hatching, they cling to their mother, only leaving her after two moltings. Hatchlings look like adult crawfish, but continue to remain in the burrow with their mother for several weeks.

    Farming Crawfish

    • Crawfish farming is done with shallow ponds that can readily be seasonally drained. The ponds need not be deep, but they are maintained in a wet/dry cycle that mimics the natural habitat of the crawfish. The crawfish are not fed, as the cover crops of sorghum, rice and soybeans provide the base for the food web that ultimately supports the omnivorous crawfish. Louisiana is particularly well suited to crawfish farming, as it has clay soil that allows shallow ponds to stay on the surface of the soil. Louisiana produces about 75 million pounds of crawfish from the farms each year.

    Louisiana Crawfish Invaders

    • Crawfish have become a popular food worldwide with repercussions felt in global ecosystems.

      The red swamp crawfish is so aggressive that it will survive in alien ecosystems, and explode into an invasisve species within years of introduction. In the U.S., it has been introduced to states from Maine to Washington largely through use as bait. The globalization of markets led to the Louisina crawfish becoming an invasive species in Africa, France, China and other countries. Where it has invaded, the crawfish pushes other species out and attacks native prey animals such as frogs and small fishes. The damage crawfish can do to ecosystems is only beginning to be studied.