The reproductive behaviors of the amphipod crustacean Gammarus palustris (Bousfield) and some insights into the nature of their stimuli

This paper describes the pair formation and mating behaviors of both sexes of the amphipod crustacean Gammarus palustris (Bousfield) in detail and sheds light on the nature of their stimuli. Males and females are guided to each other by water-borne attractants. Only after contact do males show evidence of distinguishing among males and females in different reproductive stages; they generally drop males and non-receptive females, begin to carry receptive females, and copulate with newly molted females. Upon contact, females at different reproductive stages assume different postures which assist the male to express appropriate reproductive behaviors. Finally, the data show that the most important stimulus for male reproductive behavior is the female exoskeleton and suggest the existence of a contact pheromone in this species.