Effects of food and shelter on aggressive activity in the crayfish Orconectes rusticus (Girard)

Abstract

ABSTRACT In a simplified laboratory environment, aggressive activity (threats, strikes, fights) of Orconectesrusticus declined with increasing availability of both shelter and food. Shelter and food interacted to determine overall aggressive activity; however, in general, shelter reduced aggressive activity more than did food over the 42 h duration of our treatments. Preferred food (fish pieces) reduced activity more than did less preferred food (Tetramin). Individual crayfish varied substantially in amount of aggressive activity. Overall, threats accounted for 16% of aggressive interactions, strikes for 46%, and fights for 38%; proportions were relatively constant among most treatments and between day and night.