Softball-Sized Cave Dwelling Spider Discovered

Posted on April 14, 2017

Front view of Califorctenus cacachilensis

Researchers have discovered a new species of large cave dwelling spider. The spider is related to the venomous Brazilian wandering spider (Phoneutria fera). It has been named the Sierra Cacachilas wandering spider (Califorctenus cacachilensis).

The new spider has been described by researchers at the the San Diego Natural History Museum, along with experts from Mexico and Brazil. It was first discovered on a research expedition in 2013 into a small mountain range outside of La Paz in Baja California Sur, Mexico. The scientists first found a large exoskeleton shed by the spider. Smithsonian Magazine reports that the spider is softball-sized but still smaller than the Giant huntsman spider (Heteropoda maxima) of Laos.

Jim Berrian, field entomologist at the San Diego Natural History Museum and an author of the paper on the spider, says in the announcement, "The first evidence we found of this species was a shed exoskeleton in the cracks of a rock overhang. The exoskeleton was abnormally big and I could tell by the eye pattern that it was in a group of spiders, wandering spiders from the Family Ctenidae, with very few species in Baja California Sur."

Dr. Maria Luisa Jimenez, a researcher at Centro de Investigaciones Biológicas del Noroeste and foremost expert on the spiders of Baja California Sur, says in a statement, "When I saw these spiders for the first time, I was very impressed by their size. In all my experience over the years collecting spiders on the peninsula, I had never seen a spider this large. I suspected that something new was waiting to be described."

Full view of Califorctenus cacachilensis

The toxicity of the spider has not been tested by Berrian was bitten by the spider and lived. He says, "Almost all spiders are venomous, but very few are dangerous to humans. I got bit while handling a live specimen of Califorctenus cacachilensis and I'm still alive. We haven't analyzed the toxicity of the venom, but most wandering spiders are not as dangerous as the Brazilian wandering spider."

A research paper on the new wandering spider was published here in the journal, Zootaxa.

Photos: San Diego Natural History Museum

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