Brazilian Wandering Spider. Image: Techuser

A new species of red-fanged venomous spiders have been discovered living in caves outside of La Paz in Baja California Sur, Mexico.

The species has been named the Sierra Cacachilas wandering spider (Califorctenus cacachilensis). An expedition to the area in 2013 resulted in the revelation of a giant, shed exoskeleton that was observed to belong to a group of wandering spiders from the Family Ctenidae. Further analysis and documentation led to its determination as a new species.

Califorctenus cacachilensis is related to the highly venomous Brazilian wandering spider and has been determined to be venomous itself, but like most wandering spiders excluding the Brazilian species, is not extraordinarily dangerous to humans. Its most distinguishing characteristic is the presence of two prominent red fangs that appear to protrude downwards on either side of its mouthparts.

Similar to other family members, the new species boasts three rows of eyes, with two on the top and bottom enclosing a row of four in between. Ctenidae spiders are typically nocturnal and the Sierra Cacachilas accordingly inhabits dark grottos and old mines throughout the Baja area.

The discovery is scientifically paramount due to the rarity of wandering spiders thus far identified in Mexico. This new species will make for one of a limited number.

Sierra Cacachilas are about an inch in length, brown in color, with yellow opistosomas and protruding chelicerae enclosed by two red condyles on either side, boasting the appearance of fangs.

Complete findings are published in the Journal Zootaxa.

“We haven’t analyzed the toxicity of the venom, but most wandering spiders are not as dangerous as the Brazilian wandering spider,” states Jim Berrian, study author and prominent field entomologist at the San Diego Natural History Museum.

Check out this video below of the new species’ relative, the highly venomous Brazilian wandering spider: