Creugas bajulus

Moved

Moved from Spiders. ID from matching to description in Gertsch 1942 & comments by Jim Berrian who has collected this species before.

… Lynette Elliott, 13 June, 2012 - 9:19am

I like how you cited the justification right up front. I wish there were a special field for this so it would be conspicuous for every specimen.

… Joe Lapp, 13 June, 2012 - 9:51am

Corinnidae?

Thinking about the rather thin legs, perhaps it's time to look in another direction (e.g. Corinnidae)? There's a certain resemblance to Falconina, for example (although that seems rather farfetched, I suppose.)

… Kevin Pfeiffer, 9 June, 2012 - 12:17am

Corinnidae

is what I've been thinking ever since I saw it resembles Trachelas. I asked Lenny Vincent who asked Rick Vetter. Rick says "I don't know this one but there are some weird Corinnids that get into the southern portions of southern California. Creugas is one of the possibilities."

I see now that I misspelled it as 'Cruegas' below.

… Lynette Elliott, 9 June, 2012 - 10:05am

Have you found any photos of Creugas? The TBA (see Bryant 1933a) could possibly match.

… Kevin Pfeiffer, 9 June, 2012 - 10:57am

Bryant 1933a

What's the title to that paper? I can't find it.

… Lynette Elliott, 12 June, 2012 - 8:33am

Should be online (perhaps there's no 'a' after the year):

Bryant E. B. 1933. New and little known spiders from the United States,. Bulletin of the Museum of Comparative Zoology, 74(6):171-193

[But, I see that I was looking at the wrong species! So Bryant 1933(a or no a) won't help you too much. ;-)]

… Kevin Pfeiffer, 12 June, 2012 - 9:46am

Description for Family Amaurobiidae

I happen to have Leech 1972 in hardcopy!

"Diagnosis of family Amaurobiidae: Six or eight eyes; if eight eyes, then in two transverse rows, all pale in color. Male with median apophysis in palpal organ. Chelicerae robust, geniculate (except for members of genus Zanomys) at base anteriorly, and bearing boss and scopula. Labium notched basally. Legs moderately to heavily spined, rarely lacking spines (as for members of genus Zanomys). Trichobothria in one or two rows on tibiae, absent on femora. Thoracic groove longitudinal when present. Cribellum and calamistrum present, but calamistrum reduced or absent in males of some species. Tarsal claws 3 in number. Claw tufts or tarsal scopulae lacking. [...]"

The description for genus Amaurobius includes mention of the cribellum/calamistrum, and no description for the male of any species of this genus says the male lacks them; however, many males are indicated as "unknown."

There are no habitus images at all in the 200-odd page paper.

… Joe Lapp, 8 June, 2012 - 8:25pm

not a recluse

This is a male spider in either the ground sac spiders or sac spiders. I'll have to do a little more research before guessing further. I'm out of time this morning. Those very large chelicerae & the protrusion off the palp should help us with the ID.

… Lynette Elliott, 7 June, 2012 - 10:04am

Amaurobius or something else in the Amaurobiidae would be my guess...

-K

… Kevin Pfeiffer, 7 June, 2012 - 3:08pm

Probably not Amaurobius

Amaurobius is cribellate. I'm not seeing calimistra on this one, despite the good angle and the sufficient clarity for ventral spines. Some Amaurobiids are cribellate, some ecribellate.

BTW, SONA says that Amaurobiidae are "lacking paired ventral spines." I can't tell whether these spines are paired, but usually the ventral ones are.

Can anyone make out what the eyes are up to? I'm inclined to peg it with a recurved PER. I can't see AER, so I can't be sure that's what I'm seeing.

… Joe Lapp, 8 June, 2012 - 8:27am

eyes

This is what I'm seeing

but there is one unknown bump that doesn't really fit which I've pointed out with an arrow. I still think I got the eyes right though.

… Lynette Elliott, 8 June, 2012 - 8:46am

Okay thanks. That makes more sense. I can see that now.

… Joe Lapp, 8 June, 2012 - 8:51am

Amaurobiidae is certainly another possibility

This spider certainly has the palp spurs like that genus/Family.

I was thinking it reminds me of Cruegas... and you know there is supposed to be one species found in southern CA. It's Cruegas bajulus. However, I can't find any reference or images for that species so?

It certainly has the coloring of Trachelas, but do they have the spurs off the palp? Also I've never seen a Trachelas male with that large of chelicerae or that dark/thin/long of legs.

… Lynette Elliott, 7 June, 2012 - 4:27pm

Not Trachelas

I just scanned Platnick & Shadab's two 1974 papers on Trachelas. All the RTAs are puny.

… Joe Lapp, 8 June, 2012 - 8:00am

Cruegas? New to me. I don't think that Trachelas males have such spurs. The images I've seen show a bulbous palp, though.

-K

… Kevin Pfeiffer, 8 June, 2012 - 3:41am

Unidentified Spider-Not Trachelas

From what I can see of the palps and the visible apophyses as well as general anatomy I would go with the corinnid Creugas. And from the locality it's likely C. bajula. This species was originally described by Gertsch in 1942 as Corinna bajula and the only locality given was Rosarito Beach, Lower California (now Estado de Baja California). Rosarito Beach is a short drive south. Bonaldo (2000) transferred it to Creugas. I collected a female at Mission Trails Park in San Diego so Cuyamaca SP would not be an unreasonable localilty. It'd be nice to have a closer look.

… Jim Berrian, 11 June, 2012 - 3:54pm

Thanks, all, for the help.

I will watch out for this spider again, and attempt to collect one if it reappears, for better confirmation and a voucher specimen, perhaps.

… Robyn Waayers, 12 June, 2012 - 10:39am

collect one

That would be great!

… Lynette Elliott, 13 June, 2012 - 9:31am

A specimen has been collected.

On the evening of June 21, this spider or one of the same type, appeared on the patio again, and I collected it into alcohol. It was delivered to Jim Berrian at the San Diego Natural History Museum on June 26 and will now reside at the museum. It was positively identified as Creugas bajulus by Jim (based on palp structure). So that is the second record of the species in the U.S.

… Robyn Waayers, 27 June, 2012 - 11:24am

Fantastic! Thank you!

… Joe Lapp, 27 June, 2012 - 11:32am

That is fantastic

It is so nice to have a specimen ID'd by an expert to verify all our hard work. Thanks so much!

… Lynette Elliott, 27 June, 2012 - 5:28pm

Creugas bajula does seem like a possible match. See Gertsch 1942 (PDF). (Thanks for the reference.) In particular: "Carapace dark reddish brown... Chelicerae concolorous with the head... Abdomen uniform light gray... Abdomen elongate, oval, moderately high... [Male:] Abdomen with a yellow scutum above at base." The palp in figure 32 is only shown retrolaterally, but seems like it could fit.

… Joe Lapp, 11 June, 2012 - 5:41pm

A lot of great info from everyone

Are we confident enough to create the guide page? I am ready to move forward if you guys think it's reasonable.

… Lynette Elliott, 11 June, 2012 - 10:44pm

I have to defer to you, Kevin, and "bcspiders." I don't even know how to confirm that this is Creugas. I can't find Bonaldo 2000 for the genus diagnosis - not that it would help me much, since the paper is in Spanish.

… Joe Lapp, 11 June, 2012 - 11:08pm

Creugas bajulus

I pulled up Bonaldo's paper to check spelling and when he transferred the species to Creugas the specific epithet changed to bajulus. My apologies for the error. I have a copy of the paper on a CD he sent me and I can send it to anyone interested. It has an English abstract but the rest is in Portuguese (Brazil). Anyway, the paper just lists the transfer w/o a redescription or figures. Gertsch (1942) has the only description. I am not a formal BG editor but I would recommend listing this as Creugas bajulus.

… Jim Berrian, 12 June, 2012 - 12:00pm