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T. sisyphoides - Cryptachaea blattea - female

T. sisyphoides - Cryptachaea blattea - Female
Bowers Park, Santa Clara County, California, USA
June 19, 2010
Size: ~ 3 mm
I beat this adult female theridiid from an oak tree near a creek. Keys out to Tidarren and I think this is the only species in my area. No visible colulus, abdomen higher than long and epigynum is raised swelling (see later image). I don't have Levi 1957c unfortunately - doesn't look like it is available?

Images of this individual: tag all
T. sisyphoides - Cryptachaea blattea - female T. sisyphoides - Cryptachaea blattea - female T. sisyphoides - Cryptachaea blattea - female T. sisyphoides - Cryptachaea blattea - female T. sisyphoides - Cryptachaea blattea - female

Moved from Tidarren sisyphoides. Thanks to Dr. Cor Vink for taking a look (he agreed with C. blattea).

Cryptachaea instead?
I don't think either of the Tidarren have the little tubercle on the abdomen (seen in your lateral view). I think this would instead be Cryptachaea. Looks exactly like images of C. blattea that I saw here, too: That species is found in CA (and apparently common there, according to Levi 1967, as Achaearanea acoreensis), but there are a couple other spp. in CA that I've never seen before. Pretty positive Cryptachaea is the right genus, though.

The longitudinal white line that Tidarren has on the back of the abdomen doesn't seem to be distinctive to only that genus.

(I was filling in the Cryptachaea page, so the info was fresh in mind and I was looking for other specimens with tubercles; that's the origin of this random comment.) :-)

Hmm -
well I remember thinking some of these spiders were so tiny that it was difficult to be confident of anything... :) Do we have epigynum shots for Cryptachaea somewhere for comparison? I'm not sure I'd want to base too much on that tubercle - I'd like to go back to the specimen and make sure it's real. Bottom line, though, is that I'm not working with spiders much right now and so I'll defer to your judgment Mandy - maybe move back to family page for now? I'll see if I can get additional input from some local experts...

Levi 1967c has diagrams of C. blattea (as Achaearanea acoreensis, pg. 179) and the description, "Epigynum with a swollen area, with openings anterior (fig. 13)." And female body length is about 3mm.

And there's also more recent diagrams of C. blattea here: I emailed Dr. Vink to get a copy of the original paper that has those diagrams, but don't have it yet (just emailed this morning).

I couldn't find any actual images of Cryptachaea epigynes, though, sorry. However, in diagrams of Tidarren sisyphoides, the epigyne looks like a pointy "beak" from the side (fig. 50, pg. 46). Do you remember it being like that? In the Cryptachaea, I think it is swollen, but not beak-like, just more like a "mound."

Sorry about this, it's probably annoying, especially if you're not working with spiders right now. Maybe Kevin or Lynette or others can double check this. I feel pretty confident this is probably C. blattea (Levi says it's common in parts of CA). It would be the first/only C. blattea for the guide, so that's kind of motivating me to figure it out.

No time to get involved (next
No time to get involved (next week I'll be free again), but it sounds like you're on the right track.

No worries
No rush whatsoever, but thanks, Kevin!

Found ventral of T. sisyphoides epigyne
Page 601 in Agnarsson 2004 here:

So comparing that to the C. blattea epigyne, do you recall which was closer? One central atrium as opposed to two small, separated openings. (Blowing up your image of the epigyne looks really close to C. blattea, but I wasn't there in person so could be totally wrong).

Thanks -
it's a little hard for me to compare that beautiful scanning EM (?) image with my crappy pic. :) I'm sure you're right, but I've already emailed some local spider experts - let's see what they say first - no rush...

Sounds good

Hmm -
my local expert is super-busy right now. Perhaps I'll get back to the specimen at some point to double-check, but feel free to move to a new species page if you're confident. You've obviously researched this thoroughly and I've no reason to doubt your (new) ID... Cheers.

I honestly do feel confident that it's a Cryptachaea instead, though would like to find someone with personal experience with C. blattea to see what they think about that species designation. I'll ask around before moving.

Agreement from Dr. Cor Vink
that it looks like C. blattea. He has personal experience with the species. Woohoo, a new page in the guide! :-D

Cool -
thanks, Mandy and Cor.

Hi Ken, Levi (1975) mentio
Hi Ken,

Levi (1975) mentions "a narrow longitudinal white line from highest point of abdomen to spinnerets". Might you have a lateral view?


The start of that line is seen here, I think -
and more is seen on the second image. If you follow the central dorsal abdomen from the carapace, there is a thick black line (or series of black marks), then an unmarked area, and then a dark mark where there is a slight tubercle, also the highest point I believe. Then one sees a bright yellow-white line extending towards the spinnerets. I don't think a lateral view would show this median line, although I could try to shoot a sort of "posterior view".

I looked at some of the other
I looked at some of the others in the Guide. It seems like they also tend to show a pair of laterally diagonal lines (as does your specimen), so that the overall result reminds me a tiny bit of the 60s peace symbol.

No, I was more curious to see the shape as I don't know the species myself; and Levi shows the protruding epigynum from the lateral view. So it's just a wish-list idea from me.


Added -
a lateral view. Hard to see the protruding epigynum in this shot, but shows the "taller than long" shape to the abdomen (about a ratio of 4:3 with a crude measurement attempt in my scope).

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