April 6th, 2007
a spider finds his name
I never cease to be amazed at how quickly mysteries are solved once I post something here on my blog. Here’s yet another example.
Back on March 9, 2007, I posted the above photo along with an account of the discovery of this spider on a high sandy bluff overlooking the Pacific coastline near Trinidad in Humboldt County, California. Here’s a little of what I wrote to jog your memories:
Now, back to the beautiful spider in the above photo. I took this photo back on October 3, 2006, while traveling in northern California. My fellow traveler found the spider moving across the path on a trail high above a beach not far from the town of Trinidad in Humboldt County. As soon as we knelt down for a better look, we knew this spider was a little unusual. At first glance, it almost looked like it had 10 legs instead of 8, but the extra pair at the front are an extraordinarily long set of pedipalps. The size of them reveals that it’s a male spider as the pedipalps of males spiders are larger and differently formed than those of a female. The carapace (top of the cephalothorax – front section of a spider’s body) was also unusual, being a little flattened, but with the eyes arranged on a raised bump at the front (click on the above image for a better view). The chelicerae (jaws) were also quite long and large.
David Shorthouse, of the Nearctic Spider Database was able to tell me that it belonged to the Family Antrodiaetidae – commonly referred to as the folding-door spiders. From there, I did a small amount of searching around to try to ID it further. A species chart on Steve Lew’s Spiders of California site seemed to narrow it down to four or possibly five species based on known range, but I didn’t have enough information to go beyond that. Based on what I’d read, I speculated that the spider might be Antrodiaetus pacificus which seemed to be of similar appearance and is quite common to that region. However, earlier today, Steve Lew dropped by my blog and left a comment to the March 9th post, kindly providing an ID for this wonderful spider. I decided to repost this spider’s photo and share Steve’s comment as it’s quite fascinating. Be sure to check out the link to the photo:
This spider is Atypoides riversi, commonly called a “turret spider.” They can be diagnosed from other antrodiaetids by the big prongs sticking out from the chelicerae of the male. They construct turrets from debris at the mouths of their burrows. A recent analysis shows them nested within the larger genus Antrodiaetus, which means that we’re supposed to call them Antrodiaetus too. But I like the name Atypoides dammit.
Here’s a picture of a turret.
Isn’t that turret amazing? I had no idea that any species of spider constructed such a thing. As I often say, when it comes to nature and natural history, I learn at least one new thing every day.
Tags: Atypoides riversi, Trinidad, Humboldt Country, California
April 7th, 2007 at 3:29 am
What a great spider, and the turret’s really something.
April 7th, 2007 at 4:36 am
I like your photo and the background of research is great too. I think the internet has done wonders for all of us. (Too bad it’s misused by advertisers of garbage too.)
April 7th, 2007 at 8:39 am
That turret is a work of art. Beautiful spider art. It is absolutely the best use of the internet, finding names for spiders and showing us the fruit of their labors.
April 7th, 2007 at 12:09 pm
No way! It just is so incredible that instinct can produce an elaborate structure like that turret. That is truly an awesome spider whether it’s ‘Atypoides dammit’ or ‘Antrodiaetus too’. I’m always frustrated when encountering these lovely Latin names. I’d love to be able to pronounce them, but I know I’m making a mash out of them as I roll them around in my head. (Although I think I can pronounce the ‘dammit’ :0D
April 7th, 2007 at 9:10 pm
-Very interesting!-I have to admit that I’d be a little nervous if one crawled on me.
April 8th, 2007 at 6:27 am
Duncan – Yes, indeed it is!
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O.W. – I never cease to be amazed at how the net helps to spread useful information around.
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Robin – Yes, it is beautiful spider art. It reminds me of some of the natural fiber art installations I’ve seen in galleries.
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Cathy – Yes! Isn’t it amazing how creatures know to create certain kinds of structures. Hey, I liked that “dammit” at the end too. Has a nice ring to it! I’m not much for correctly pronouncing Latin names, so I’m not much looking forward to mangling a bunch of them on Tuesday evening when I give that slide presentation at the Canadian Museum of Nature. Should be good for a few laughs! (o:
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Larry – I didn’t quite know what to think of this spider when we first examined it. It was certainly different than anything I was used to up here in Canada, so I wasn’t sure if it was cable of inflicting a bite.
April 10th, 2007 at 6:01 am
Wow – that turret is beautiful. All held together by spider silk stronger than steel, it looks like.
Glad you were able to get an id on that very adapted spider. I’m usually happy to get things down to family on my own, and ecstatic if I recognize similarities that suggest a genus, but it’s always a kick to have an expert weigh in to confirm (or even steer you onto a different track!). When it comes to arthropods I find myself just throwing out possibilities and hoping someone will notice and correct or elucidate.
April 10th, 2007 at 6:25 am
Wayne – Yes, isn’t that turret something special? I was reading about folding and trap door spiders recently, and the strength of the silk that holds the refuges and doors together, etc.. is rather astounding.
I was very glad to get an ID for that spider! I didn’t think I’d ever find out what it was as I’m not from that region and know next to nothing about such spiders. That’s where the net is so helpful, although you do have to post the images and then try to get at least a few useful bits of info posted so that others can find it.