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ID please

Started by Guest_teleost_* , May 06 2008 01:23 PM

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10 replies to this topic

#1 Guest_teleost_*

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Posted 06 May 2008 - 01:23 PM

I decided to start learning technique for photographing inverts and learned a lot this weekend. These are not great pics but I'd like to know what they are if possible.
Thanks in advance for your help.

All from IL/IN border Kankakee drainage.

Below came from basically stagnant water, deep silt bottom and heavily vegetated adjoining medium large river. This crayfish had distinct, small, black spots on it's carapace separated by an estimated 1/8".

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Below came from a gently flowing ditch with sand and silt bottom mix. This stream is roughly 4.5 water miles from the Kankakee. At this time of year the stream was sparsely vegetated.

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And last, a silly question but can below be identified from this photo? Came from the first site listed above.

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#2 Guest_Newt_*

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Posted 06 May 2008 - 01:27 PM

Handsome crawdads! I'm no good at IDing them, but your other bug is definitely a dragonfly, probably an aeshnid (darner). You didn't happen to get a picture of the face from the front, did you?

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#3 Guest_teleost_*

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Posted 06 May 2008 - 01:33 PM

Handsome crawdads! I'm no good at IDing them, but your other bug is definitely a dragonfly, probably an aeshnid (darner). You didn't happen to get a picture of the face from the front, did you?

I did not get a head on shot. Is a head on shot typically required for ID? If so, I'll make sure and get them in the future.

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#4 Guest_centrarchid_*

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Posted 06 May 2008 - 01:38 PM

First crayfish of male form II of genus Procambarus but not red swamp P. clarkii. I think either prairie P. gracilus or white river P. acutus.

Second crayfish also male form II of genus Orconectes but not O. rusticus, O. luteus, O. propinquus or O. immunis all of which occur in Illinois drainages. Form II gonopods most similar to those of Orconectes virilis (a.k.a northern, northern fantail, virile crayfish). Color on back very intense but I have not seen many up your way.

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#5 Guest_Newt_*

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Posted 06 May 2008 - 01:40 PM

I did not get a head on shot. Is a head on shot typically required for ID? If so, I'll make sure and get them in the future.

Well, the structure of the mandibles helps to distinguish the families. You could either get a head-on shot, or use a probe to pull the mandibles out and shoot them that way. The nymphs usually do not appreciate this procedure, however. To get a species ID, I at least would need to put the specimen under a scope. Maybe there are some better entomologists on the board who can sight-ID it.

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#6 Guest_teleost_*

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Posted 06 May 2008 - 02:36 PM

Thanks Centrarchid. You made me remember that I can pull a list of crayfish known from this county to help.
Cambarus diogenes
Procambarus acutus
Orconectes virilis
Orconectes rusticus
Orconectes propinquus
Orconectes immunis

I guess I should have started with this list or maybe even bought a book! I need to get motivated towards crayfish ID.

Thanks to you as well Newt. I thought it might be a long shot but they're such an interesting creature. I could not resist a photo or two.

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#7 Guest_centrarchid_*

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Posted 06 May 2008 - 02:40 PM

The "Crayfishes and Shrimps of Illinois" by Page of the Illinis Natural History Survey goes for about ten dollars.

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#8 Guest_ashtonmj_*

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Posted 06 May 2008 - 02:42 PM

Based on the slender claws, rostrum shape and aerola width I would say your first specimen is Procambarus acutus.

I will second the call that the second crayfish sure looks like a form II Orconectes virilis. The aerola width looks correct as well as the usually red claw tips. The tubercles on the claws look a little weak however they are in the right place. I have seen them with that intense of a motteling before.

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#9 Guest_jdclarksc_*

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Posted 06 May 2008 - 04:03 PM

Based on the slender claws, rostrum shape and aerola width I would say your first specimen is Procambarus acutus.

I agree the 1st is definately a male P. acutus

Nice shots Uland!
Clark

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#10 Guest_airbrn1187_*

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Posted 07 May 2008 - 03:41 AM

Those pics turned out GREAT!!!

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#11 Guest_scottefontay_*

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Posted 07 May 2008 - 07:00 AM

Those pics turned out GREAT!!!

Don't know abut the cray but Newt was correct it is most likely Odonata anisoptera aeshnidae. To get any farther, as Newt also said, would require a scope and a key and counting mouthparts and body hairs...