Dominance Order in the Crayfish Orconectes virilis (Hagen)

Abstract

Aggressive behavior, observed in the field, was duplicated in small laboratory groups. Subservient reactions followed: (a) active fighting, (b) a strike with the chelae, (c) a threatening posture and (d) non-threatening proximity of a dominant animal. Both males and females established a straight-line dominance order. As a check on these observations, a technique of "social inversion" was devised in which the crayfish were transferred in order of dominance, at 5-day intervals, to new aquaria. In these inverted groups the original dominance order was re-established.