Wood lice, Sowbugs and Crayfish in Colorado

A Crayfish or Crawdad found on 31 August 2010 in the Elevenmile Lake, Park county Colorado. It was at least 4 inches long. The pictures are not clear since they were in the water with some breeze.

This is probably an Orconectes (Gremicambarus) virilis. The normal range for that species would include Colorado. But, there are about 100 different species of Crayfish in the U.S., so this is not for sure. The tentative identification was made with the help of Dr. James W. Fetzner Jr. from the Carnegie Museum of Natural History in Pittsburgh, PA, and the internet site he recommended at iz.carnegiemnh.org/crayfish/NewAstacidea/species.asp?g=Orconectes&s=immunis&spp plus iz.carnegiemnh.org/crayfish/NewAstacidea/infraorder.asp?io=Astacidea .

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Family: Cambaridae
Genus: Orconectes (Gremicambarus)
Species: virilis


Sowbugs and Wood lice are common names for these Terrestrial Crustacians. They are not insects, and are more closely related to shrimp than to insects. According to Wikipedia, some of them, in the genus Armadillidium can roll up into an almost perfect sphere as a defensive mechanism, hence these have common names such as Pillbug and Roly-Poly.

The one pictured is in the genus Armadillidium, since they can roll up into a ball. They have seven pair of legs.

The next two pictures were taken at the Fountain Creek Nature Center, Just south of Colorado Springs, on 16 July 2008.

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Isopoda
Suborder: Oniscidea
Genus: Armadillidium
Species: A. vulgare (probably)


Defensive mechanism caused by me kicking some dirt in his direction.
Some more Sowbugs, of various sizes, found on the bottom side of a board that had been laying on the ground in Colorado Springs, CO on 13 November 2008.