Monday Mimic #10 Followup

Ted MacRae correctly identified this weeks ant mimic as a jumping spider, Myrmarachne plataleoides (image to the right).

There are a lot of obvious giveaways in this shot, but you still need to stand in awe at how good a job the spider does. It makes up for a lack of antennae, and an overabundance of legs, by holding its forelegs up, alongside the head. Its huge anterior medial eyes are colored to match the head when not viewed directly, and the posterior lateral eyes are enlarged, with darkened pigment around them to mimic an ant’s eyes. Also, the cephalothorax and abdomen are deformed and narrowed considerably.

As a bonus, I came across a spectacular video (below) of Myrmarachne plataleoides (or a closely related species) showing off its retinal scanning behavior. Jumping spiders have narrow, horizontal band retinas in their large anterior eyes which they scan from side to side with muscles inside the head. This is very similar to the retina structure and head motions of diving beetle larvae, which I discuss in detail here.

For more, you can read my previous post about jumping spider vision, or check out some adorable macro videography of jumping spiders by Thomas Shahan.

5 Comments

  1. Ted C. MacRae February 8, 2011 12:35 am

    Cool video – where’d you find it?

    http://beetlesinthebush.wordpress.com

  2. Michael Bok February 8, 2011 12:43 am

    On Vimeo, it came up as a search result from Google: http://vimeo.com/5788607