Individual Distance in Crustacea

III. The Spider Crab Microphrys bicornutus


Division of Biological Sciences, University of Michigan, Ann Arbor, Michigan 48109, U.S.A.


The effects of density and environmental complexity on distance of separation when agonistic acts were executed were studied in the spider crab Microphrys bicornutus. Crabs were held at one of two densities and either in a simple (no structural complexity) or complex environment (rocks added to the aquarium). Behavior patterns and the distances at which they were executed were observed in a neutral container. Analysis of the 580 behavior-distance measurements indicated effects of both density and environmental complexity.