Cray Species ID

I think it is a Procambarus acutus because I heard that they were very common in the collection location.

I found him under a rock near the Watertown Dam on the Charles River in Watertown, MA. The dam is breached so that water flows over the top of it. I caught this guy only 20 feet past the dam. The water flows quite fast.

I'm sorry I can't get any better pics. I put him in with my Orconectes immunis and they snacked on him last night. (I can tell by the gonopods that it was a male)




Another guess would be Orconectes virilis. There are only 5 species of crays native to my state.

Given the choices of P. acutus and O. virilis, I would say that's a O. virilis, only based on the red tips and shape of the claws. To be sure I would need a better picture, but O. virilis is what it looks like.

Edited by fishlvr, 02 April 2008 - 04:57 PM.

Given the choices of P. acutus and O. virilis, I would say that's a O. virilis, only based on the red tips and shape of the claws. To be sure I would need a better picture, but O. virilis is what it looks like.

From what I can see I, also agree some Orconectes sp. What are other possibilities? From images I can not distinguish O. virilis from O. rusticus. Must see some gonopods, possibly layed out on a piece of black paper for contrast.

It looks like O. limosus, which are native. The orange black tips on the claw are the best thing I can give you with that picture. Virilis do not have that color on the claws. If you rub your finge along it's cheek does it get stuck because of alot of tiny spines? There are two larger spines on both limosus and virilis but limosus (spiny cheek crayfish) has a patch of spines. If you had gonopods you should have taken a picture of them! I can show you pictures of limosus and virilis gonopods later and an interactive key that might work for your region.

Interactive Crayfish of Maryland Key

Give this a try. It went live just a few days ago. You can also back track a little bit to the non-interactive key.

I would definatly aggree that it is an Orconectes species. However I would disagree that O. virilis doesn't have orange on the claws. I have collected that species all over Canada & the US & they always have orange on the claws. Also to identify the species via the gonopods you would need to have a form 1 male.

It looks like O. limosus, which are native. The orange black tips on the claw are the best thing I can give you with that picture. Virilis do not have that color on the claws. If you rub your finge along it's cheek does it get stuck because of alot of tiny spines? There are two larger spines on both limosus and virilis but limosus (spiny cheek crayfish) has a patch of spines. If you had gonopods you should have taken a picture of them! I can show you pictures of limosus and virilis gonopods later and an interactive key that might work for your region.

You will get much better pictures of crays if you take them in water. That way you will also be able to see the coloration. A better picture CLOSEUP of the top of the carapace with flash would also be helpful.

Edited by Canadiancray, 04 April 2008 - 10:57 PM.

I did not say there was not ORANGE on the chela I said there was not ORANGE and BLACK. Virilis has a single color on the chela99.9% of the time and it is typically a red red-orange with chela much larger than the crayfish pictured. Form II virilis are distinguishable from Form II limosus.

Like I said before, I put him in with my O. immunis and they ate him.

I'll try to get more this week.

Edited by diburning, 06 April 2008 - 12:22 PM.