Wild cray ID (IL)

Lisa · Post by **Lisa** » Fri May 26, 2006 5:50 am

I found a bunch of these little guys in a creek in southwest IL, about 60 miles east of St. Louis, MO. This one is approximately 1" long and I didn't see any larger than 1.5". The creek is in the woods and the depth varies, depending on season, from a few feet deep to nearly dry; the bottom is gravel and sand, muddy around the edges, which is where I found most of the crays. There are crayfish burrows around the edges of the creek, but whether they belong to these guys, I don't know--they looked pretty big unless these are juvies rather than a dwarf species. The camera really picked up the orange tips on the claws and the afternoon sun made it look a little more orange than brown, but otherwise the image is a fairly good representation of what I saw when I scooped one up into a container:

Here are two, undisturbed right where I saw them:

(I didn't know what they were, so I just took pictures, not crayfish.

)

CanadianCray · Post by **CanadianCray** » Fri May 26, 2006 3:58 pm

There is no way to tell 100% what the species is without looking at a Form 1 males gonopods. There are 23 species of crayfish found in that state. They look like juveniles to me & this is the time of year where you will find mostly babies & small juvies as the rivers & creeks will be loaded with them. Being a Juvi makes it even harder as there colors & patterns are usually totally different from the adults.

Check out this site for a list of all species in your state.
http://iz.carnegiemnh.org/crayfish/coun ... linois.htm

Lisa · Post by **Lisa** » Fri May 26, 2006 7:19 pm

Ah--so just a few species, then.

Thanks for the link--I can go back to the creek any time, so I'll watch these guys and see whether I can't figure out what they are as time passes. Whatever critters are making the holes in the bank are probably their parents. It'll be fun to see what the little guys turn into!

CanadianCray · Post by **CanadianCray** » Sat May 27, 2006 3:47 am

Geese I must have been sleeping there. I didn't notice what you said about the burrows. Considering there are burrows & the diamond pattern on the crays back. I would say that it is an Orconectes immunis.

Here is an adult notice the pattern on the tail.

Here is a Juvi notice the orange on the claw tips.