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An Introduction to Crayfish

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Welcome to the International Association of Astacology! If you’ve found yourself on this page with the hopes of learning more about crayfish, you’ve come to the right place. Astacology is a sub-discipline of biology that specializes in the study of crayfish: freshwater crustaceans that are both ecologically and economically important. There are many astacologists around the world researching crayfish, but there is much that we have yet to discover about these animals. As members of the International Association of Astacology, our aim is to encourage the scientific study, conservation and wise utilization of freshwater crayfish.

Here are a few interesting facts about crayfish that you may not know:

  • Crayfish, crawdad, crawfish, yabby, freshwater lobster and mudbug all refer to the same animal.
  • There are over 640 species of crayfish in the world, with two centers of diversity, one in the Southeastern United States and the other in Southern Australia.
  • Crayfish and lobsters look similar to one another, and are closely related, but all crayfish live in freshwater, whereas, all lobsters live in saltwater (the ocean).
  • The smallest crayfish reach only 2 cm (0.8 in) in length, while the largest can exceed 80 cm (31.5 in)!
  • Crayfish eat just about everything, from plants, insects, leaf litter to small fish. Crayfish even occasionally cannibalize one another!
  • Crayfish are very important prey items in stream ecosystems and are the primary food source for many animals including fish, amphibians, reptiles and birds.
  • Crayfish have adapted to all sorts of environments, from streams and lakes to caves and even burrows that they dig to reach the ground water. Next time you're in a stream or lake, flip some rocks to see if a crayfish darts out.
  • Crayfish, like many tropical fish, are found in a rainbow of vibrant colors and patterns.
  • Crayfish are edible. In fact, many cultures depend on crayfish as a source of protein.
  • Because of the risk of introducing invasive species and spreading diseases, crayfish, whether dead or alive, should NEVER be released or dumped into the wild.

Crayfish News, the quarterly newsletter of the IAA is now available to everyone for free. Navigate to the Crayfish News Archive page under publications to get the latest issue.



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