Need ID on Native Dwarf Cray

[wonword]

Hello,
I caught this guy in the St. Croix river under a rock, near Hudson WI! I figured it was a baby of a regular crayfish. But it never grew over 2" long. It has alot of blue on it, with red rings around its pinschers. It also (when it matured) had a bright red spike on its back. Can anybody ID it? Sorry I have no better pics, he was eaten when I had to tear down my small tank and I put him in my larger tank?

 

[black_sun]

Well, in WI (as well as your location state) you'll find the following known species:

Cambarus diogenes
Orconectes immunis
Orconectes luteus
Orconectes propinquus
Orconectes rusticus
Orconectes virilis
Procambarus acutus acutus
Procambarus gracilis

Of those, you can rule out Procambarus gracilis and Cambarus diogenes, as they are burrowing crayfish that would not have been found under a rock. Of the remaining then, you can rule out Procambarus acutus, Orconectes virilis, Orconectes rusticus and Orconectes luteus due the size they reach as adults. That leaves you with Orconectes immunis and Orconectes propinquus as possible options. And in relation to closest size, Orconectes immunis would be the closest match. But neither normally display such colors (or patterning like in the picture) and neither have spike(s) on the top of the carapace.

So, I'm inclined to think you caught an introduced/invasive species. A very interesting one at that.

Anyone else have any idea?

 

[wonword]

Well, in WI (as well as your location state) you'll find the following known species:

Cambarus diogenes
Orconectes immunis
Orconectes luteus
Orconectes propinquus
Orconectes rusticus
Orconectes virilis
Procambarus acutus acutus
Procambarus gracilis

Of those, you can rule out Procambarus gracilis and Cambarus diogenes, as they are burrowing crayfish that would not have been found under a rock. Of the remaining then, you can rule out Procambarus acutus, Orconectes virilis, Orconectes rusticus and Orconectes luteus due the size they reach as adults. That leaves you with Orconectes immunis and Orconectes propinquus as possible options. And in relation to closest size, Orconectes immunis would be the closest match. But neither normally display such colors (or patterning like in the picture) and neither have spike(s) on the top of the carapace.

So, I'm inclined to think you caught an introduced/invasive species. A very interesting one at that.

Anyone else have any idea?

Wow, Thats interesting! I wish I wouldnt have let wolf fish eat it!

 

[fishman1978]

here in wisconsin we call them cowboys

 

[le patron]

looks like a regular old crawdad to me. same as the ones i catch here up north

 

[wonword]

ive caught other crays before, and they get much bigger. i have also not seen them with this amount of blue or a red spike