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Crayfish of Wisconsin

WAV volunteers are asked to keep an eye out for the invasive rusty crayfish when doing their regular macroinvertebrate monitoring.

According to the book “Crayfishes and Shrimp of Wisconsin” (Hobbs and Jass, 1988) Wisconsin waterbodies are home to about seven species of crayfish.  The most common are Cambarus Diogenes, Orconectes propinquus, and the invasive Orconectes rusticus.  Although usually found in water, crayfish can live out of water if their gills are kept moist.  They can also utilize atmospheric oxygen if dissolved oxygen in water becomes too scarce.  Most of the crayfish of Wisconsin mate in fall and females lay their eggs in the spring (some have more extended breeding periods).  General information about each of the species found in Wisconsin, taken from the book “Crayfishes and Shrimp of Wisconsin”, follows.

A simple crayfish identification guide was developed in 2012. >>View the crayfish identification guide(1.5 MB pdf)

 

 

 

Cambarus diogenes
Diogenes Photo by Dale WestabyC. Diogenes, the devil crayfish, is one of the most widespread species of crayfish in the United States and in Wisconsin, as it’s found in every major watershed of the state.  It was first observed in Wisconsin in 1882.  This type of crayfish often lives in burrows of still waters such as ponds, ditches and even wet fields, but is also known to be found burrowing in stream bottoms and banks.   Burrows are usually three or four feet deep and generally are branched, with two or three openings at the surface.  These openings are covered by mud “chimneys”, which are thought to be used as protection by a crayfish that might need to expose its gills to the air to obtain oxygen if the dissolved oxygen in the water in the tunnel is low. 

 

Blue Crayfish Blue Crayfish
A blue colored rusty crayfish was found in WI in the summer of 2005 by DNR staff. At the site they were found, it was reported that they were relatively common, and were represented by several age classes, and made up approximately 50% of the crayfish we saw.  Others were colored normally. Joan Jass from the Milwaukee Public Museum offered some insight to its color: "While some crayfish species naturally have blue in their color patterns, there also have been many times in the literature when reports have been made of blue individuals appearing in populations of otherwise non-blue species.  The best explanation I have heard is that such occurrences are due to the species having the blue as an underlying color naturally, but usually this is overlain by an orangish color with the end result of that being greenish.  The blue individuals are those that for some reason have an inability to process carotene in the diet, leaving them to exhibit that underlying blue. Blue individuals are discussed under the species color notes in our WI crayfish book, which is available as a pdf under the MPM's WDNR ATRI grant-sponsored Wisconsin Crustaceans Homepage

Also Dreux Watermolen from DNR said this about the crayfish: "FYI - This is most likely a hybrid individual (cross between nonnative Orconectes rusticus and native O. propinquus [commonly called the blue crayfish]), but without having the specimen in hand I couldn't be sure. A blue body color phenotype usually is inherited as an autosomal recessive trait, something that seems to be fairly common in hybridizing populations (which rusties and blue apparently are). See: "Hybrids Consummate Species Invasion" by Wade Roush in Science (277[5324]:316-317, 1997.

Contacts:
Kris Stepenuck

608.265.3887 or 608.264.8948
kris.stepenuck@ces.uwex.edu

 

The majority of the information contained on this page taken from “The Crayfishes and Shrimp of Wisconsin” by H.H. Hobbs III, and J.P. Jass. Milwaukee Public Museum, 1988, 176 pp.  Photos are courtesy of Dale Westaby.

Milwaukee Public Museum crayfish website
This site provides some great information about crayfishes of Wisconsin.
> Visit Site



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