Discrimination of conspecific-built chimneys from human-built ones by the burrowing crayfish, Fallicambarus fodiens (Decapoda, Cambaridae)

Abstract. The vast majority of tested juvenile crayfish of Fallicambarus fodiens consistently preferred conspecific-built mud chimneys over similar-looking human-built chimneys. When the chimneys were surrounded by transparent acetate sheets, the crayfish no longer discriminated between conspecific-built and human-built chimneys. This suggests that visual cues were not important in allowing the crayfish to discriminate between the two chimney types. In the absence of chimneys, significantly more crayfish showed an initial preference for mud saturated with water that had contained conspecifics, over similar mud saturated with distilled water. This indicates that chemical cues play a role in allowing these crayfish to discriminate between the conspecific-conditioned mud and the control wet mud. The preference of F. fodiens individuals for conspecific-built chimneys appears to be based, at least in part, on chemical cues, possibly in addition to tactile cues.