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Photo#291168
Crab Spider - Ozyptila praticola

Crab Spider - Ozyptila praticola
Groton, Middlesex County, Massachusetts, USA
June 19, 2009
Size: 5mm

Images of this individual: tag all
Crab Spider - Ozyptila praticola Crab Spider - Ozyptila praticola

John and Kevin
Can you guys look at the following
59789 55153 38462 7658
and let us know if any of them are Ozyptila?
We're trying to perfect our search image for head shape, swollen femur, spined tibia, etc. to identify the few Ozyptila images out of the mass of Xysticus photos that we get here. Thanks,

 
Hi, John and Jane
59789 - looks like Ozyptila to me, though the femure is longer and more slender than a 3:1 ratio beween length and width (but maybe that's because its a male?). I think I see only 2 macrosetae on Tibia I.

55153 - I see only 2 macrosetea on tibia I. Other than that I'm not sure. Maybe this picture is a candidate for the frass bin?

38462 - I would choose Ozyptila over Xysticus, based on the slender front carapace and tibia macrosetea. Can't see much fine detail, though.

7658 - Xysticus There are four pairs of macrosetae on tibia I (I had to enlarge the picture to see them all).

 
Hi, John and Jane- I defer
Hi, John and Jane-

I defer to John on this matter, not least because we just moved into a new apartment and I will have my hands full for the next few days.

-Kevin

Moved
Kevin, this species lives close to Canada, and on both coasts. It'd be interesting to see if there are some found in other parts of the country.
Thanks for getting this one to species, and take your time with any of the others. It sounds like you have a lot of other things to do.

 
Oops, I take back my one comm
Oops, I take back my one comment -- Paquin and Dupérré do have the species in their book. I must admit, I didn't recognize it from the drawing of the epigyne. Only when I read through Dondale/Redner's keys did it become clear to me.

-K

 
Wow! You were fast. Were you
Wow! You were fast. Were you standing behind me just now. :-)

-K

 
Good timing
I'll be eating dinner in a few minutes, then editing and posting photos from my weekend trip to see Puffins and lots of other birds.

Ozyptila praticola (kmp-5718)
Hi, Tom-

I've been so busy with resettling here, the baby, and now a possibly pending move, that I didn't think I would ever get back to your specimens. But here's the first one. Took me longer than it should because apparently this Holarctic species (and therefore one I should have/could have recognized from here) is not found in Canada, which happens to be the territory covered by two of my most commonly reached for references. I had to go to Dondale and Redner's 1954 article for the Journal of American Arachnology to find a species that is in our "local" guide book by Michael Roberts.

So, you have here the Holarctic (Old World and New World) species Ozyptila praticola.

I haven't hooked up my microscope camera, yet, but you can find some ventral views showing the epigyne here (scroll down to 'praticola': http://www.spiderling.de/arages/Fotogalerie/Galerie_Ozyptila.htm

You'll notice that the carapace is marked by radiating lines in the lateral areas (Dondale/Redner) and the sternum is (generally) marked by black spots at the center and near the margins (ibid). I'll try to take a ventral shot this week. The epigyne is rather pronounced in appearance and probably recognizable to the naked eye (or with lupe).

Interestingly, Dondale and Redner note under localities "Washington : Seattle. Massachusetts : unspecified locality. Europe" and for range: Pacific and Atlantic coasts of United States.

Okay, that's all for tonight.

-K

Moved
John, it looks like you're right. This is the first Ozyptila I've photographed, so I wasn't expecting anything other than Xysticus.

Looks more like
Ozyptila sp. I'm looking at the narrowing of the carapace in the eye region, and what appear to be only 2 pairs of ventral macrosetae on tibia I (there would be more than 2 pairs for Xysticus - I'm not sure the smaller setae just past the macrosetae on Leg I in the first picture count as a 3rd pair of macrosetae). Also, the femur of Leg I looks to be stouter than what it would be for Xysticus, just about right for Ozyptila. (though that might just be the angle from which they appear in the photo).

Nice pictures.

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