Can Anyone Identify This Spider?

Question

Found in Sunnyvale, California in our bedroom. Just was crawling up the wall. Further description on photo caption:

http://www.flickr.com/photos/janella/303229668/

Answer 1

Your spider is absolutely positively a Zoropsis spinimana.

Photo here:
http://www.calacademy.org/science_now/invasive_species/zoropsis_spinimana.html

"These large spiders are currently invading the San Francisco area."

Photo here:
http://spiders.ucr.edu/images/zorspi.jpg

Diagram of identifying marks and patterns:
http://www.americanarachnology.org/JoA_free/JoA_v29_n1/arac_29_01_0111.pdf

Article and photo:
http://www.physorg.com/news10271.html

"San Francisco Bay-area residents are being asked to help keep track of a new arrival -- the Zoropsis spinimana spider.

The spider, a native of Mediterranean and northern Africa coastal countries, is brown with grayish spots. It's about two inches in length when it stretches its legs.

Scientists aren't certain when or how the arachnid migrated to Northern California, but they told the San Francisco Chronicle it is an apparently harmless spider."

Article: http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2006/01/26/BAGHRGT0E11.DTL
"House spider migrant setting up in Bay Area
Scientists ask public for help in studying how species adapts
Zoropsis seems to be harmless: Calm and slow-moving, it didn't try bite or otherwise hurt Darrell Ubick, an expert at the California Academy of Sciences, who placed a member of the species on his arm.

Still, Ubick and his academy colleague, entomologist Charles Griswold, are asking Bay Area residents to watch for Zoropsis as part of a long-running research project to study how the spider species is settling down in the Bay Area.

They ask anyone who spots something that looks like Zoropsis around the house to avoid the temptation to squish it. Rather, let them know about the sighting by e-mailing a description of the creature to [e-mail]. A digital photo of the spider is even more helpful, Griswold said."


This is NOT a brown recluse. A brown recluse has a fiddle shape on is back as you can see here: http://z.about.com/d/p/440/e/f/19570.jpg See how there is a brown tiny little violin/fiddle shape on it?

Also, the recluse has a distinctive eye pattern; "A more definitive diagnostic feature is the eye pattern -- brown recluses have a semi-circular arrangement of 6 eyes in 3 groups of 2 while most other spiders have 8 eyes."

http://www.uky.edu/Ag/Entomology/entfacts/struct/ef631.htm

Edit Note: Member bo_fra did not have the Zoropsis spinimana listed in their list of possibilities until after I posted this answer. I went over every single post with a fine toothed comb to see if anyone mentioned the Zoropsis spinimana to make sure I was not duplicating someone else's effort if the answer had been found. The Zoropsis spinimana and one of the links I posted with this answer appeared in bo_fra's altered answer after I'd posted my own. I also posted on the Flicker account as "weheartjon" at ten to 7pm central time. Since there are no time stamps, anyone who posted before me can copy the answer I posted and pose it as their own original answer when that is not the case. The name of the spider isn't exactly common and stands right out. Plus everything else on his list are simple spider names, not specific species names. Also a clue is the Spinimana was added to the bottom of the list and he took one of my links. All for a few silly points. At least Google Answers pays real money so there isn't juvenile sniping. It would be nice if people were honest.

Answer 2

I do not think it is a brown recluse. A photo of a brown recluse is at Wikipedia:
http://en.wikipedia.org/wiki/Image:Brown_recluse.jpg

I think it might be a wolf spider or related, non-poisonous species. I will look further then edit this answer....

I'm back now...
Gee, I give up! I went down the list from Wikipedia's page:
http://en.wikipedia.org/wiki/Araneae_families
copied the latin name into google images, and never saw a spider like yours out of the bizzilion I looked at. I have the creeps now!

Please let us know if you get a positive ID from a pro!

TIA

PS - as I write there are already 52 answers! Wonder what the record is for most answers to a question...
Spiders seem to be popular, esp with the nice photos!

Me again with another edit. I think a later response by
bo_fra, with photo, has it!
I quote, "very close to Zoropsis spinimana
http://www.calacademy.org/science_now/invasive_species/zoropsis_spinimana.html
It appears to be an invasive species from the Med!

Way to go!

Answer 3

I think it's some variety of wolf spider. I did a quick Yahoo images search on both wolfs and brown recluses to review, you might want to try doing that search yourself for peace of mind. Brown recluse spiders in California are very rare. Brown recluses latin name is vio(something) because of the violin shaped marking on it's thorax, where the legs come out, not the big butt part. They also tend to be found in large colonies, not individually. Brown recluses are one of two poisonous spiders found in California, the other being the well known and distinctive black widow. Brown recluse bites cause the area of skin around the bite to become necrotic (to die and turn black) and this will keep happening while the poison runs it's course. There are some really yucky pics on Yahoo Images if you want to see. I have often found two wolf spiders together, the females are larger, so you may want to look around to see if this one had a partner. If it is a wolf it is not poisonous, but can bite you. I read somewhere once that spiders drink out of your eyes while you are asleep! I, personally, have woken up twice in my life to find a spider straddling my eye. Very creepy!

Answer 4

By the looks of it I would say it some sort of nursery web spider (family Pisauridae), most likely genus Dolomedes. I am not too familiar with spiders from this region of the world, I am from souther Canada and I have never seen this specimen before.

Maybe this page could be of assistance:
http://bugguide.net/index.php?q=search&keys=dolomedes&search=Search

In any even it does not look like any of the more dangerous species in North America, so i dont think it is of immediate concern. Although at the size described it could easily give a nice bite that will hurt for sometime, so be careful none the less.

hope this helps!

Answer 5

It's not a brown recluse. The one you have has no clear violin shape on its back, and its rear segment is not big enough in relation to its head. (Brown recluse has a significantly larger rear segment than head.)

It doesn't look like anything you need to worry about to me. I think we have those around my house, and the worst they will do is hiss at you if they are extra large.

BTW, when brown recluse bites you, the venom is necrotic. That means that it rots the flesh. If you get bit by a brown recluse, *you won't die*, but you must go and recieve emergency treatment as soon as humanly possible to mnimize the damage, and avoid surgery to extract the affected tissue. Those bites can leave huge holes in a person if they don't get professional treatment immediately.

Answer 6

Not sure. Big as a silver dollar is large for a brown recluse. May be a wolfe.
Can you see its eyes? If so, a brown recluse has 3 pairs of eyes that form a comma like shape. that should be easy to see. They also have what is called a fiddle mark on their back-it looks like a violin. But it may be hard to identify. Just step on it. Don't take a chance.

Answer 7

The Brown Recluse is a small spider that has a necrotizing bite (the venom causes death of the tissure where it bites), but silver dollar size is much to large for this spider. They live in dark areas like linen closets and sheltered nooks and crannies. This looks more like some wolf spiders that I have seen, some of them get huge. They are carnivorous and eat other insects.

Answer 8

Steven Y got it right, it is a species of mouse spider. Some of them can have a really painful bite, but do not require medical attention. They also, as you can tell by the photos, have large and powerful fangs. They have been known to pierce boots.

Answer 9

It's a wolf spider

Answer 10

I don't think it's a brown recluse because recluse are found in the south, not in California.

The legs look hairy and recluse aren't known for hairy legs.

This one is as big as a silver dollar, and recluse aren't that big normally.

The little black thing on the abdomen doesn't look like a violin.

If you're not sure, capture it and have it id or just stomp it. Better safe than sorry.