Individual discrimination in the big-clawed snapping shrimp, Alpheus heterochelis

Abstract

Rahman et al. (Rahman, N., Dunham, D.W. and Govind, C.K. (2001). Mate recognition and pairing in the big-clawed snapping shrimp, Alpheus herterochelis. Mar. Fresh. Behav. Physiol., 34, 213–226.) demonstrated discrimination by snapping shrimp between former mates and unfamiliar conspecifics, but did not test individual discrimination. In the present study, snapping shrimp showed discrimination between familiar and unfamiliar same-sex conspecifics by preferentially entering that arm of a Y-maze leading to familiar individuals. Furthermore, after being exposed to water from the home tanks of unknown individuals, they later showed an elevated response to this water, if the direction from which the water came into their tank was changed to be novel. This indicates that test subjects associated a familiar chemical stimulus with its location in the environment. This discrimination could only have been made if that chemical signature were recognised as different from that of another chemically familiar individual. This result also demonstrates that the water surrounding an individual contains sufficient (chemical) information to allow discrimination of one individual from another.