Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Superfamily Astacoidea - Crayfish

Adult Rusty Crayfish - Orconectes rusticus Reddish crayfish moving around mostly above water before entering burrow perhaps - Procambarus clarkii crayfish Crayfish Crayfish Astacoidea Crayfish crawfish - male
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Crustacea (Crustaceans)
Class Malacostraca (Malacostracans)
Superorder Eucarida (Eucarida (Crabs, Crayfish, Shrimp, etc.))
Order Decapoda (Crabs, Crayfishes, Lobsters, Prawns, and Shrimp)
Infraorder Astacidea (Crayfishes and Lobsters)
Superfamily Astacoidea (Crayfish)
Other Common Names
Mudbug, Crawfish, Crawdad
Synonyms and other taxonomic changes
see (1)
Explanation of Names
Astacoidea Latreille 1802
Numbers
Two families in North America: Cambaridae, which is widespread, and Astacidae, of which one genus (Pacifastacus) is found in the Pacific Northwest and the headwaters of some rivers east of the Continental Divide.
Identification
If you want a crayfish sexed or ID'ed to species, it is most helpful to have a good ventral view of the abdomen so that the pleopods (swimmerets) are clearly visible.
What to Photograph for ID:
Dorsal view of full carapace
Rostrum and Acumen
Areola
Dorsal view of Chelae ("claws")
Gonopods - the first set of pleopods are modified in males as the sex organs known as gonopods, and rest against the abdomen between the last set of legs. A good up-close photo of the gonopods can be critical for an ID of many different species. If at all possible, gently left the left gonopod away from the abdomen with a tooth pick and photo both lateral and mesial views with a macro capable camera or lens.
Print References
Hobbs H.H. (1989) An Illustrated checklist of the American Crayfishes (Decapoda: Astacidae, Cambaridae, and Parastacidae). Smithsonian Contrib. Zool. 480. iii+236 pp.