Identification, Images, & Information
For Insects, Spiders & Their Kin
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Spider found in mud caves - Loxosceles

Spider found in mud caves - Loxosceles
Anza-Borrego Desert State Park/Mud Caves, San Diego County, California, USA
November 4, 2012
I saw these spiders about 80-100 feet back in a mud cave. There was no light and I did not see any other life plant/insect in the caves.

Moved from Spiders.

I'm also thinking a recluse here. The carapace shape looks right, and if you look closely at the full-sized version, I think the near lateral pair of eyes is visible. It's not very clear though, so it could be an illusion.

The stance also appears recluse-ish. None of the Nesticidae images I've seen online have the tarsi bent outward like they are here (Nesticids seem more cobweb-like in posture?).

after looking up Neoanagraphis chamberlini I think you guys are right with Loxosceles. However, are we certain enough to start a new species page with this one? Perhaps we should leave it at the genus level?

Steve Lew's list also has L. deserta for San Diego County, but we do have the local expert's expert saying L. palma for the area. I wouldn't want to argue with that, though I'd still feel safer keeping it at genus level until we have more info.

I guess that would depend on how much overlap there is in range, I don't see L. palma listed on our range map? And whether or not a cave is L. palma's natural habitat?

Moved from ID Request. Any chance you'll be going back there and can collect one or get better shots?

Not likely
I have asked others on the trip if they have better photos but so far no luck. I am not likely to return soon and don't know about collecting permits for a national park. I may try to get a trip going with some local expert friends.

Thanks for your help.

Since it's in a cave maybe it's one of the Nesticidae?

Compare with

It's hard to tell in some of the images we have but the leg ratio looks different to me. The Nesticidae I see don't seem to have the third pair of legs as long? Is there one that does?

I'm not sure
I haven't studied that family much if at all. The legs look thinner too. Recluse might be possible the only things that bother me are the cave habitat and the bulbous looks of the abdomen. I wish the image was clearer.

Cave habitat
I wish the image was clear too!

I also sent this to my local expert who sent it to his expert. Response:

It looks like Loxosceles (recluse spider) which means it would be L. palma from that area. Some recluse spiders are cave-dwellers. However, many desert spiders are tan and long legged (Neoanagraphis is one) that they can't be ruled out either.

That would be nice, I don't think we have that one represented in the Guide yet.

I think the second leg on the right hand side is a regrowth too, it should be longer/thicker compared to the other side.

Looks a bit like a Recluse (Loxosceles) to me. Lets see what the others think.