NESTEDNESS IN ASSEMBLAGES OF METAZOAN ECTOPARASITE AND ENDOPARASITE OF MARINE FISH

Assemblages of metazoan ectoparasites of 79 species and gastrointestin al helminths of eight species of marine fishes were analysed to examin e whether nestedness is related to sample size, abundance, species ric hness, and prevalence of infection, and whether the use of z-scores or Monte Carlo simulations yields different results. No significant diff erences in the number of nested assemblages were found with the two me thods, and neither sample size nor abundance, but prevalence of infect ion of ectoparasites was correlated with nestedness. Species richness was significantly correlated with nestedness only when fish species wi th fewer than three parasite species were not excluded. Differential c olonisation probabilities are the most likely cause of nestedness.