Rusty crayfish are known as ‘invaders’ they have invaded portions of Minnesota, Wisconsin, Ohio, New Mexico, New York, New Jersey, and all of New England with the exception of Rode Island. Rusty crayfish were spread by non-resident anglers who brought them north to use as fishing bait. They were usually found in the states of Kentucky, Tennessee, Indiana, and Illinois. They also spread when people buy them as pets and when they don’t want them anymore they put them in the water. The Rusty crayfishes habitat are usually in still pools of water or fast-moving streams. They like rocky and covered areas to hide from predators.

Depending on the water temperature their eggs hatch in 3 to 6 weeks. Maturity is considered to be at a length of 4.4 cm for females 8.8 cm long for males. Rusty crayfish usually mate in early spring mid summer or early fall. The expelled eggs are attached to swimmerets underneath the crayfishes abdomen. The female crayfish could lay up to 80 to 575 eggs. Rusty crayfish are scavengers the young crayfish eat invertebrates and fish eggs. Older crayfish eat aquatic plants, snails, clams, leeches, aquatic insects, other crustaceans, and fish eggs. The population of the Rusty crayfish has expanded since 1960 throughout northern Wisconsin lakes and streams. They are called Rusty crayfish because they have two rusty colored spots on their shoulders and on the tips of their claws it is a rusty color.

Author: Katelynn P

Published: 03/2008

Sources: http://www.michigan.gov/dnr/0,1607,7-153-10370_12145_25065- 33021--,00.html http://animaldiversity.ummz.umich.edu/site/accounts/information/Orconectes_rusticus.html

Photo Credit: AlexandOwOer Early http://www.aeflash.com/pics/crawdad.jpg