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Immature male dorsal - Marpissa obtusa - male

Immature male dorsal - Marpissa obtusa - Male
Austin, Travis County, Texas, USA
July 1, 2010
Size: 2.5mm excl. palps
Found in my car, which only allows me to place it in the Austin area somewhere. Recent visits were to McKinney Roughs Nature Park, Barton Creek Greenbelt at Gus Fruh, and Barton Springs, but it could also have been at my house or anywhere else.

Images of this individual: tag all
Immature male dorsal - Marpissa obtusa - male Immature male side - Marpissa obtusa - male Immature male side face - Marpissa obtusa - male Adult male dorsal - Marpissa obtusa - male Adult male side - Marpissa obtusa - male Adult male side face - Marpissa obtusa - male Adult male ventral - Marpissa obtusa - male Ventral palp - Marpissa obtusa - male Retrolateral palp - Marpissa obtusa - male

I have an exact location for
I have an exact location for them! My house! I just found an adult male on my driveway. I can look for the female right here.

Moved from Jumping Spiders.

Marpissa obtusa it is
G.B. Edwards says the spider most closely resembles Marpissa obtusa, so I think it's safe to call it one. We'll need a new guide page for it. Also, G.B. says that, according to Logunov (1999), the female is currently unknown, so there's a good opportunity to actually contribute some science here, if only I could find a few more.

Now's the time to look (since
Now's the time to look (since this one just matured)! Ideal would be to find a pair or males and females in close proximity.


It's a Marpissa
I posted palp shots. It's a Marpissa. SONA is placing it correctly, as I was able to find a fourth pair of small spines on tibia I using UT's better scopes.

I just spent some time working through Barnes 1958 but could not find a good match. The only Marpissa listed for Texas that isn't in this paper is Marpissa bryantae, whose description I haven't seen yet.

Marpissa obtusa
I haven't looked closely at all of the Marpissa species at, but it looks to me like Marpissa obtusa.

Nice images, BTW; glad you were able to get the images of the pedipalps.


Yes, the palp kinda matches o
Yes, the palp kinda matches obtusa, but the description in Barnes doesn't. "A pair of pale, closely placed spots in posterior part of ocular area and eyes surrounded by black...First femur brown dorsally, with a prolateral light band... All [but first] femora pale with two ventral bars and a prolateral black transverse bar... [All but first] tarsi pale. Dorsum of abdomen pale..." And on an on with more differences.

Marpissa obtusa
Hi Joe,

First, you have to remember that these descriptions are based on examining the (mature) specimen under alcohol/water by means of a microscope; the salticids, more than any other family, change appearance dramatically when viewed this way. Furthermore, colouring and pattern can vary in most every family. But even so, the descriptions of the legs and dorsum do for the most part match. And most importantly, the images of the pedipalp (Logunov, 1999c - ventral, Barnes, 1958 - retrolateral) do indeed match. There are a couple features that are difficult to see in your images, due to lack of depth of field and/or slight positional rotation, but they are there. In his description Barnes (1958) also writes that the "male abdominal pattern [is] similar to that of M. sulcosa", which he has depicted. Look at fig. 42 and you'll see a dorsal pattern very similar to that of your specimen.

You're welcome to send me this (and any other) specimens, BTW.


Thanks Kevin. I'm still gett
Thanks Kevin. I'm still getting the hang of this. I guess it's best to consider the genitals to be completely diagnostic.

The M. sulcosa drawing has some similarity, but my eyes aren't screaming "that's it."

I had Allen Dean look at this and he wasn't willing to make a call from it, deferring me to G.B. Edwards, who I've emailed.

If it is a Phanias, you may have a hard time placing it as the genus doesn't seem to be well studied.

Thanks for the info, but it's
Thanks for the info, but it's not Phanias. I was only able to see 3 pairs of ventral spines on tibia I at home, but with UT's better scopes I was able to locate a short 4th pair. Marpissa.

Not likely a Phanias
Well, after piercing a hole completely through the cephalothorax, I managed to get the right palp off. It looks nothing like the Phanias palp shown in figure 52.69 of SONA, which is also found in the Maddison paper. I'll take it into UT for decent photos. I'll reverse the image before posting. My confidence in SONA is eroding - this was an easy key to genus. The specimen is in pretty good shape despite the hole.

I should clarify. SONA repor
I should clarify. SONA reports that they are found in Texas, but Texas A&M does not list any.

Now an adult
This fellow became an adult sometime within the past week. I made a new entry for the last instar, since his length and looks are both different now.

Thanks for all the advice on raising him. He's been easier to raise than some others I've got who don't seem able to catch things that fly.

Any chance
that your excellent photos look anything like my blurry mystery spider (image #283721) taken in the Dallas area?

Moved from ID Request.

Great photos!
Wish I could help more with your astute questions - I would have also guessed that this was a penultimate male, but I'm not sure. There are even rare genera of north american salticids where the female has swollen palps (I'm forgetting the genus right now). I've never raised spiders, but would like to learn as well - Jay Barnes has done this many times and has some tips in his comment here. Let us know what happens!

Can anyone tell if he's penultimate? I'm thinking of preserving him for ID, but I only want to do it if it can be ID'd. I'll throw in a suggestive photo (ehem!).

Under a scope I'm seeing a da
Under a scope I'm seeing a darkened conical extension angled out from the tip of the distal segment, but I'm not seeing the complexity I expect of an embolus. How do I rear such a tiny critter to adulthood? What's the best way to catch fruit flies if I let a banana rot?

You could collect aphids or springtails...
Both of those types of bug are frequently found in large masses (I guess you'd have to go out huntin' for them). They might be easy to collect, though, and feed him. I actually breed Pholcus phalangioides and then use the spiderlings as food for my tinier spiders. Not sure why I sort of latched on to that method. It just seems to work.

Fruit flies
I forgot to mention that it's possible to buy fruit flies online if you don't want to try the catching method. I get my crickets from Fluker's and they used to have fruit flies there, too, but I just checked and the page acts like they're sold out or something. It doesn't display a price or an "add to cart" button. But if you do a google search for something like "buy fruit flies," lots of other options are available. I've personally never went the fruit fly route (yet) so I can't really give you any pointers.

He's eating a fruit fly right
He's eating a fruit fly right now, thanks to rotting bananas on my porch. The possible immature Corinnid I caught isn't going for its fruit fly though.

The corinnid...
...might actually be nearing its next molt. Spiders stop feeding for a while before they molt. They do need hydration, though, to make sure their molt goes smoothly (otherwise they get stuck).

Thanks! The Salticid is still
Thanks! The Salticid is still eating well -- loves fruit flies -- but I released the Corinnid due to the combination of having trouble feeding her and how quick she moves.

Sweeping the grass
gets lots of tiny bugs. The "bad" part is I keep finding more spiders, too. Just take a big mouthed jar or pitcher, hold it with the mouth near the ground, and quickly move it forward scooping the bugs up.

LOL! Thanks everyone! I've b
LOL! Thanks everyone! I've been scooping up little hoppers from my light and plopping them in the jar. He catches most of them.