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 likes rays of a sun, 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. A low profile results 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 also rendered them the nickname 'flatties'. Selenopid Crab Spiders 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.
Scientific Name: Selenops spp.
Size (Adult; Length): 8mm to 13mm (0.31in to 0.51in)
Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.
Legs: Spiders have four pairs of legs and these are attached to the cephalothorax.
Pedipalps: Small appendages near the mouth used as taste and smell organs.
Cephalothorax: Contains eyes, head, mouthparts, and legs.
Abdomen: Contains various organs related to digestion, reproduction, and web-making.
Spinnerets: Used in the production of spider silk for fashioning webs or catching prey.
NOTE: Unlike insects, spiders have both an endoskeleton (internal) and exoskeleton (external).