Selenopid Crab Spider (Selenops spp.)
Detailing the identifying qualities of the Selenopid Crab Spider, including physical features and territorial reach.
Updated: 11/1/2017; Authored By Staff Writer; Content ©www.InsectIdentification.org
The flattened bodies of Selenopid Crab Spiders allows them to hide in tight spots between rocks and other hard places.
Selenopid Crab Spiders have long legs that they sometimes extend out sideways, casting a resemblance to resting crabs. A more familiar resting pose has all eight legs splayed out, giving them a larger appearance.They are found in the warmest regions of the U.S. as well as Mexico. Covered in brown speckles and bands, they are easily camouflaged in nature.
The body of this genus of spider looks quite typical for arachnids when viewing it overhead. Their most remarkable feature, however, is best seen in its profile. Additional concealment comes from a flattened body. The abdomen is flat, as if pressed down on with a spatula. This lean profile allows them to squeeze into small crevices and remain hidden from danger. This physical feature has given them the nickname "flatties".
They are nocturnal and hide during the day. At night they emerge and quietly rest, often overlooked in the darkness. For this reason, sightings are rare despite their year-round presence.