Small female crab spider protecting her egg sac. Crab spiders, order: Araneae, Superfamily: Thomisoidea, Family: Thomisidae, are named so because they resemble crabs, with a flattened body and the two front pairs of legs angled outward with the inner pair often longer than the outer pair. They also move like crabs, scuttling sideways and backwards. There are 170 genera and over 2,000 species..They do not build webs like other sedentary spider species, who can be consider oportunistic or passive hunters, crab spiders actively hunt and ambush. This crab spider was found under a rock near the junction of the Lower and Upper Faulty Trails in the Sandia Mountains, east of Albuquerque, New Mexico.