# Some Alberta Crab Spiders



## jsloan (May 11, 2010)

Thought I'd post images of the various species of _Xysticus_ males I found last year, and also so far this season.  Quite a variety from just around my place!  Most were collected by pitfall traps.  By far, the most abundant at the moment is _X. emertoni_ (and it's also the largest).  Maybe I'll add images to this thread as I find more species (including females) throughout the summer.  A few look too much alike for me to tell them apart by general appearance, so I identified each one by its palp.  My goal is to get photos of every Alberta species (I might have to do some travelling for that - don't know if they're all found in this one area).

_Xysticus emertoni_:






_Xysticus ferox_:






_Xysticus britcheri_:






_Xysticus obscurus_:






_Xysticus ellipticus_:






_Xysticus luctuosus_


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## John Apple (May 12, 2010)

Very cool indeed, you must have put in some time searching for all males only for the photo session


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## zonbonzovi (May 12, 2010)

Nice, pics, sir!  Any advice on location placement of pitfall traps for crab spiders?


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## jsloan (May 13, 2010)

zonbonzovi said:


> Nice, pics, sir!


Thanks!



zonbonzovi said:


> Any advice on location placement of pitfall traps for crab spiders?


Most of these turned up in traps I placed in tall grass, either around the edge of my lawn or in mostly open fields (some shrubs and other low vegetation in the area, too).


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## jsloan (May 13, 2010)

John Apple said:


> Very cool indeed, you must have put in some time searching for all males only for the photo session


No, I just found mostly males is all.  These photos are from several different photo sessions.  Usually, I photograph unusual specimens soon after returning with them from the traps, then I put them in vials with dated labels and numbers.  Later, when I get around to identifying them, I can link each one to its correct picture.


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## jsloan (May 17, 2010)

Here are a few females to go with the males:

_Xysticus obscurus_:







_Xysticus ferox_:







_Xysticus ellipticus_:







Color is not always a good feature to use in identifying these spiders to species, because it is variable.  I've recently found some _X. ferox_ that are a little darker/browner than the one shown above.

Here are two version of a female Xysticus emertoni:

Light version:






Darker version:


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## TheTyro (May 17, 2010)

Crab spiders are some of the few spiders I rarely take the time to try and identify...they all look so similar at a glance..heck, they all look similar up close...a formidable task but it's great you are taking it on. A project like that would take me years, mostly because I can't kill spiders ahead of their time...I'd have to wait for them to die naturally before I tried getting a look at their spidery bits. 

The only type I try identifying are ones that look terrifically different than the sort I usually see...but that isn't often, and that also seems difficult because there tend to be a lot of em that look similar to one another, even though they look..unique...if that makes any sense.

I'd love to see a Xysticus ellipticus in person though, it's abdomen looks like a pebble! Thats awesome.


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## Toirtis (May 17, 2010)

Give me a shout when you are in Calgary...I would love to help search for what you do not have down here.


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## jsloan (May 20, 2010)

Toirtis said:


> Give me a shout when you are in Calgary...I would love to help search for what you do not have down here.


Will do.  I might be passing through there later this summer, if I can make the trip, heading to the Lethbridge area to collect some _Latrodectus herperus_.


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## jsloan (May 20, 2010)

TheTyro said:


> The only type I try identifying are ones that look terrifically different than the sort I usually see...but that isn't often, and that also seems difficult because there tend to be a lot of em that look similar to one another, even though they look..unique...if that makes any sense.


It makes a lot of sense.  Even specimens of the same species can look different from each other.  I can barely distinguish between the look-alikes without checking the palp or epigyne.  Fortunately, the palps are unique and its easy to separate the species with them; the epigynes are a little tougher, but not too bad with a little practice.


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## Toirtis (May 20, 2010)

jsloan said:


> Will do.  I might be passing through there later this summer, if I can make the trip, heading to the Lethbridge area to collect some _Latrodectus herperus_.


Leth is good, Medicine Hat seems better...Paruroctonus boreas plentiful there, too.


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## sygdom (May 20, 2010)

Wow those are some really cool pictures. Just shows you how diverse these things really are. I tried setting up some pitfall traps over the weekend and unfortunately had no luck, at least in the spider department . I am going to attempt to relocate them this weekend and hopefully have a little better luck. I was going to put them under some of my trees and bushes.


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## jsloan (Jun 20, 2010)

I've been lookin for a female of this species for a long time.  Finally found one about a week ago on a poplar sapling.

_Xysticus punctatus_:







Side view:


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## VinceG (Jun 20, 2010)

Really nice pictures!
Could you ID this one, I'm from Montreal. The abdomen is not really shown in the picture so I don't know if you'll be able to ID it.

http://img824.imageshack.us/i/araigne8.jpg/

Thanks!


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## jsloan (Jun 20, 2010)

Normally these spiders are difficult to identify from pictures, because they look very similar to one another; but, I can see part of the palp in your spider called the "tegular apophysis," which is fairly large and sticks out to the side just a bit.   I'd have to examine it close up to confirm the species, but your spider might be _Xysticus emertoni_.  

Here's a picture of a _Xysticus emertoni_ palp to give you a better idea of what I mean.  The tegular apophysis is the long thick, black pointed structure that looks kind of like a knife blade and is pointing to the left.  In most other species of _Xysticus_ that structure isn't as large, but there are some species other than _X. emertoni_ in your area that come close and it might be one of them as well.  So, _Xysticus emertoni_ is just a best guess for an ID, but that's what I'd go with for now.  

This _Xysticus emertoni_ palp is from a specimen I collected in Alberta:


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