August, 2018

Pirate Spider

The rather spiny, and very small (about 7 mm in length), spider shown here is not one of the more well-known species. Pirate spiders (Mimeticus sp.) don't make webs, don't usually end up in bathroom tubs, and are not considered dangerous to humans, so they are generally not even noticed. When they are found, it is usually in low vegetation, and they are often just hanging out, doing nothing in particular. Their nondescript appearance can be reminiscent of other kinds of spiders, especially orbweavers (which sometimes hide away from their distinctive web) and crab spiders. The reason for the common name has to do with prey preference. These arachnids specialize in eating other spiders, usually stalking them in their webs, then biting them on a leg. I've only found two individuals that were actually in the process of eating another spider. One had killed a long-jawed orbweaver and the other a sac spider. Many other spiders will also prey upon their cousins as well as insects, but pirate spiders have venom that is optimized to quickly kill arachnids. In spite of that, I've also seen one eating a midge, so they are just as catholic in their diet as most predators.