Title

Interspecies aggression and social dominance in crayfish

Date of Award

2009

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Biological Sciences

First Advisor

Paul Moore, PhD

Second Advisor

Sheryl Coombs, PhD (Committee Member)

Third Advisor

Paul Morris, PhD (Committee Member)

Fourth Advisor

Thomas Kinstle, PhD (Committee Member)

Fifth Advisor

Verner Bingman, PhD (Committee Member)

Abstract

Interspecies aggressive competition was proposed to exist in closely related species with niche overlap. However, the relationship between inter-intraspecies aggressive competitions is unknown. Specifically, the cost in intraspecies aggressive competition could be reduced when the aggression became ritualized, and could be reduced further with the establishment of social dominance. It is unknown whether or not such mechanisms exist in interspecies interaction. Three related crayfish species Orconectes rusticus, Orconectes virilis, and Procambarus clarkii were used as a model, we began to answer questions concerning the interspecies aggression in closely related species with niche overlap. The work presented here shows that first, interspecies aggression in crayfish appears to be ritualized and follows similar behavioral steps of escalation as intraspecies aggression (Chapter II). Second, dominance relationships can be established across species and these dominance relationships appear to last for some period of time (Chapter III). Finally, there is some indication that previous fight experience and status recognition may be an important part of interspecies interactions (Chapter IV). Taken together, these results suggested that the patterns of aggressive behavior in these three crayfish have evolved from the aggressive behavior of the common ancestor of crayfish.