127, see text Castianeira is a genus of ant-like corinnid sac spiders first described by Eugen von Keyserling in 1879.

[6] The opisthosoma is not constricted,[7] and has an elongate to oval shape to mimic that of ants.

In addition to the ant-like coloration, the abdomen has white scale-like setae.

Some mimic ant behavior as well, waving their front two legs as if they were antennae or bobbing their abdomen to look more ant-like.

[9] Certain species found in Texas mimic fire ants to prey on them, while some species use Batesian mimicry, appearing like velvet ants to take advantage of their aposematism in order to deter predators.