spider - Amaurobius borealis

Amaurobius borealis

Not that it's necessary, but a close-up look under the microscope confirms John's determination: Amaurobius borealis.

-K

… Kevin Pfeiffer, 18 March, 2010 - 4:56pm

Moved

Moved from Amaurobius.

… tom murray, 4 December, 2009 - 3:54pm

Moved

Moved from True Spiders.

… tom murray, 4 December, 2009 - 7:55am

Cribellum?

Any chance of seeing if there is a cribellum on this specimen? Can you get a detailed ventral shot of the spinnerets? I wonder if this might be an Amaurobius sp. (Amaurobiidae)?

Nice spider, whatever it is.

… John Sloan, 2 December, 2009 - 11:27pm

Ventral of the spinerrets

I'll put this guy in alcohol later today, and get a ventral shot, and also try for a better shot of the palps.

… tom murray, 3 December, 2009 - 7:44am

I'm more inclined to say Call

I'm more inclined to say Callobius, but it's tantalizingly difficult to see the various details in the lateral view of the palp.

-Kevin

… Kevin Pfeiffer, 3 December, 2009 - 3:00am

Close ups added

I added detailed pictures of the palps and the spinnerets.

… tom murray, 3 December, 2009 - 10:22pm

Amaurobius

The basic structures are there, but it doesn't match any of the species I have (A. borealis, A. ferox, and A. similis). A. borealis looks closest, but your photo is tilted, looking down at the palp a bit from the top (a straight-on shot would be better). Also, your picture is of the right palp and the left is usually the one used in diagrams. That said, I'm very sure the genus is Amaurobius. The RTAs look good, too (I'm looking at the diagrams in Paquin and Duperre). Let's see what Kevin thinks. He's got more resources than I have.

If no one recognizes this as another species, I can always dig out my A. borealis male and see if that palp looks the same from the angle in your picture.

… John Sloan, 3 December, 2009 - 11:48pm

A (very) quick look this morn

A (very) quick look this morning didn't turn up anything, but I'm willing, for now at least, to concede John's Amaurobius. :-)

-Kevin

… Kevin Pfeiffer, 4 December, 2009 - 1:00pm

Left palp photo added

It's still tilted like the other one, but that was the best I could get with the way the spider held them. Hope this helps:-)

… tom murray, 4 December, 2009 - 8:03am

A. borealis

It helped a lot. I took out my specimen and looked at the palp from the same angle and it looks like a match. I'd say you have a male A. borealis there. :)

Great set of pictures.

… John Sloan, 4 December, 2009 - 3:50pm