October 20th, 2007
another spider gets a name
A couple of posts ago, I wrote about some of the spiders that we encountered while at Richardson Grove in the redwoods. Most particularly, I mentioned a very large spider found in a towel atop the picnic table at our campsite. It looked to be a Tarantula of some kind (see photos below), but I’ve had very limited contact with such spiders — just a couple of captive exotic species owned by friends back home — so asked for comments from readers.
A couple of you offered suggestions of IDs. As well, I did a bit of looking around on the net and couldn’t seem to find anything that looked quite the same and might be found in the same range. It then occurred to me to email Steve Lew who had so kindly identified a Turret Spider that my friend and I found last October near Trinidad, California. Within minutes, Steve came through with the following info:
That’s Calisoga, family Nemesiidae. I believe that both Calisoga longitarsus and C. theveneti occur in Humboldt County. Humboldt County is too wet and cold for real tarantulas.
With this new information, I did a bit more looking around online and found this page about Calisoga longitarsus. The description states:
Calisoga are similar in appearance and movement to tarantulas. However, they are not quite as hairy and the pubescence is more similar to velvet. When threatened these spiders rear back to position fangs for a strike.
The description does match up quite well with my own observations. I’d describe the spider that I saw as being more velvety than hairy — and, in fact, it was quite a lovely creature. And, as you can see in the above photo, it did rear up to expose its fangs when it felt that it might be threatened by me.
I did a little more checking beyond this and found some info about Calisoga spiders in a comment to a post archived in the Arachnoboards forum. It is part of a discussion between members who were trying to ID a spider that was probably similar to the one that I found at Richardson Grove. One of the members posted this interesting little bit of information:
I sent an email message to a Dr. Vincent (a professor at Fullerton College) and he was kind enough to reply. I also found some additional links based on his information. Here’s his reply:
“How nice, and unusual, to get a good physical and behavioral description. I am sure that your spider is in the genus Calisoga (formerly Brachythele) and in the family Nemesiidae (formerly Dipluridae). I mention the old names in case you have an opportunity to look up the spider in older yet common spider books (American Spiders by Gertsch and How to Know the Spiders by Kaston). I too remember how aggressive Calisoga is. You should not try to pick it up with your hands, it will bite. Although the common name is funnel-web tarantula, it is not a true tarantula. California tarantulas are docile and can be picked up by hand.
So, there you have it — a couple of bytes of info gleaned about Calisoga spiders. As always, I’m amazed at home much info can be found via the internet.
