A Jumping Spider - Thiodina sylvana

Eve, the writer of the lovely Sunny Side Up blog, recently posted this macro photo of a Jumping Spider. Ever since I was but a wee lad, Jumping Spiders were the one species of spiders that I was never really afraid of. Perhaps because they themselves seemed to not possess a fear of me. Often times I have seen these little spiders on my desk while I am working- and they are not shy about jumping onto my notebook or even my arm. These spiders almost seem friendly- and for that, I have liked them.

Unfortunately, my freedom from arachnophobia in regards to this spider has been tainted.

At least two medical sources list this spider as being venomous:
  1. Medical Toxicology of Natural Substances
    By Donald G. Barceloux, Ed Krenzelok
  2. Toxicon
    By International Society on Toxinology
The Medical Toxicology of Natural Substances had this to say concerning the Jumping Spider Family (Phidippus):

In vitro studies suggest that Phidippus venom is cytotoxic and capable of producing necrotic lesions. Envenomation produces a sharp, painful site that may develop into urticarial (author's note: urticarial: rash like, burning - remember that the latin name for the Stinging Nettle plant is 'Urtica' as well) swelling and pruitus (author's note: pruitus: itchy sensation) lasting several days to a week. A small ulcer potentially may develop in the area of the bite, but the formation of necrotic lesions in humans is not well documented. Treatment is supportive.

I have been bitten by a fairly large Jumping Spider before. I made the mistake of grabbing it and clutching it in my hand so that I could take it outside. It bit me on the palm. Its bite was a sharp pain- but that was it. I didn't have any of the symptoms mentioned by the article. There were no visible or lingering signs that I had ever been bitten.

Jumping Spider Facts:
  1. Jumping Spiders can jump. Typically between 10 to 40 times their body length. That would be like a 6 foot man being able to jump a distance of between 60 to 240 feet. By comparison- the current world record for a long jump by a person is 29.4 feet.
  2. There are over 4000 described species of Jumping Spiders. They are the largest group family of spiders.
  3. Jumping Spiders have the best vision of any spider species. (source)
  4. Jumping Spiders will stalk their prey- much like a Lion or a Tiger. Once they see their target- they will creep slowly toward it- stop- then creep forward again- and then stop- etc- until it is finally close enough for the big pounce attack! (source)
  5. Jumping Spiders can leap as far as they do because of special muscle contractions that happen in their body. These muscle contractions force fluid into the spider's legs which causes the legs to extend quickly. (source)
  6. The Thiodina sylvana (the species pictured) species of Jumping Spider was described and named by Nicholas Marcellus Hentz. Mr. Hentz was a fascinating man. He lived during the 1800's and described over a 100 of species of spiders and insects. He once also lived in my hometown of Florence, AL- he and his wife were the directors of the women's college that was located in Florence at the time. His wife was an accomplished novelist. He once gave a museum his insect collection (and presumably spiders were in the collection)- it numbered over 30,000 species! (source)
As I was searching for more information on Thiodina sylvana, I actually stumbled upon a website that sells these spiders (or at least they did in 2006- the date of the price list.) The seller listed the common name of this spider as the "Woodland Jumper" and was selling a female for $7.50. (source)


aristide said...

signor ragno!!!

Eve said...

I was hoping you would do an article on this fellow Daniel! Great information and isn't it wonderful there were and are people who really love to learn about all the creatures around us!!

The Giraffe Head Tree said...

I've always liked these spiders, too. They're friendly little creatures and they seem to eat up the bad critters so I say live and let live.