Crab Spiders, Thomisidae

Thomisidae is a family that holds around two thousand species of crab spiders that can be found throughout the world. Although the name crab spider has been used to refer to a large number of species, it is most often used to refer to members of this family, especially the flower crab spider. Many members of this family have flat bodies that resemble those of crabs and others hold their two front legs in positions that crabs are known for or move in sideways motions as crabs do.

Although every species of crab spider within this family is able to produce silk, the silk is not used to create webs; rather it is used to create drop lines for hunting and mating purposes. Most crab spiders use ambushes to capture their prey, waiting beside fruit, flowers, and other plants for insects to pass by. Some species shelter under crevices in bark or in leaf litter and hunt in the same area, but no matter the area in which they hunt, all crab spiders grab their prey with their strong front legs and inject venom into their prey to immobilize it. The bites of these spiders are deadly to insects, but their venom is not known to be strong enough to affect humans.

Image Caption: A colorful crab spider from Goa. Credit: Palmfly/Wikipedia (CC BY-SA 3.0)