Spider of the Week: the Twin-flagged Jumping Spider (Anasaitis canosa)

This week’s spider is inspired by a beauty that I found in my shower (!) a couple weeks back. Not entirely sure why she was trying to set up camp in there, unless perhaps she was thirsty. Anyway, here are a few glamour shots, plus a couple cool facts about this species. Enjoy the holiday weekend!

Anasaitis canosa from Austin, TX. This species gets its common name from the two large silvery-white spots on the top of its pedipalps.

Anasaitis is a small, currently paraphyletic genus (part of a clade with Corythalia. See: Zhang & Maddison 2013) . Most species are found in the Caribbean, but A. canosa occurs throughout the Southeastern United States.

These spiders are tiny! (Hand and knee of a ~5’8″ woman (myself) for scale).

This species often feeds on ants, as individuals live in leaf litter of forest floors. One observational study of A. canosa‘s hunting behavior found that this species will follow its prey along complex routes, and are perhaps even capable of internalizing and triangulating prey location. See the following paper for more info. It’s a very fun read! Hill 2006 Predatory pursuit of ants.

Like many other spiders, females produce egg sacs that they guard until the eggs hatch. Here’s a picture of my new friend with her newly produced sack. Hopefully I’ll get to see a few little jumper spiderlings sometime soon!

A. canosa female with her egg sac (top right).

Last but not least, here’s a great video that makes the “twin flags” and  beautiful iridescence of A. canosa much more apparent.