MICHIGAN CRAYFISH ID,PLEASE

dreamspirit · Post by **dreamspirit** » Wed Jul 25, 2007 4:01 pm

Hi, I need some help to ID this baby crayfish i caught in a Michigan inland lake.. The body is a pale blueish/gray and at the end of each claw is a blue color and then the tips are a orangish color.
Any ideas????
Thanks!!
Tracey

badflash · Post by **badflash** » Wed Jul 25, 2007 4:52 pm

Looks like a Rusty to me. O. Rusticus

This is a new invasive species to this part of the country. I just collected a bunch in upstate NY and they are not suposed to be here either. Very agressive and disruptive to the aquatic environment.

Check http://www.iisgcp.org/research/projects ... es0598.htm

dreamspirit · Post by **dreamspirit** » Wed Jul 25, 2007 7:48 pm

Thanks for the link.. I emailed the Professor at Notre Dame and sent the pics so if it is a Rusty i can dispose of it.
Thanks

dreamspirit · Post by **dreamspirit** » Thu Jul 26, 2007 6:16 am

ok, the guy at Notre Dame got back with me and this is what he said....("That is definitely not a rusty crayfish. Without a closer look at the actual specimen, I can't be certain what it is, but there are a couple of native species that are possibilities.")

bulrush · Post by **bulrush** » Thu Jul 26, 2007 10:21 am

Looks like orconectes virilis. I find these here in Kentwood, in Kent County. The orange tipped claws are common in o. virilis, but not guarenteed. But I do see the red lines between the tail segments, that's indicative or o. virilis. Do a search on Google images for more o. virilis.

Shade and pattern of the shell varies a lot depending on their environment. I see some that are dark and some that are light coming from the same pool. So I use:
- Lack of rusty spot on side to rule out O. Rusticus
- Orange tipped claws to determine O. Virilis
- Thread thin red lines between tail segments, and on end of tail, to determine O. Virilis.