HOST BODY-SIZE AND HABITAT AS FACTORS AFF ECTING THE DISTRIBUTION ANDABUNDANCE OF THE COPEPOD CLAUSIDIUM-SP (CYCLOPOIDA), ECTOSYMBIONT OF THE GHOST SHRIMP CALLIANASSA-GARTHIRETAMAL, 1975 (CRUSTACEA, THALASSINIDEA)

This study analyzes the importance of body size and habitat of the gho st shrimp Callianassa garthi, as host factors affecting the patterns o f distribution, abundance and fecundity of the ectosymbiont copepod Cl ausidium sp. Ghost shrimps from two different habitats were collected and compared in the copepod abundance, fecundity, and number of oviger ous and mature females per host. Experimental estimates of the carryin g capacity and colonization rates of copepods were also carried out. R esults revealed that the aggregated distribution of copepods among hos ts and the host body size were the principal factors determining intra population size. Host habitat indirectly influenced the size of copepo d intrapopulations through changes in the body size structure of the g host shrimp population. Intraspecific competition among copepods seems to play a minor role in regulating intrapopulation size, as indicated by the low intensity of the density dependence of copepod fecundity. We discuss the possibility that the size of copepod intrapopulations i s limited by recruitment.