Cryptic substrate preference in crayfish

Abstract

Selective substrate choice is a form of crypsis commonly used as a predator avoidance strategy by crayfish. Substrate preference in crayfish of the genus Orconectes was tested and analyzed regarding cryptic behavior related to predator avoidance. Crayfish showed strong preferences for cryptic substrates such as rocks and woody debris over the less cryptic substrate sand. Overall, crayfish showed the strongest preference for big rocks than any other substrate choice, spending a signficant majority of their time on this substrate. Crayfish also displayed more agitated behavior when placed on less cryptic substrates such as sand and small rocks and had more relazed postures on big rocks and in woody debris.