Influence of Host Size and Sex on the Endohelminth Infracommunities of the Red Rockfish Sebastes capensis off Northern Chile

The relationship between host size and sex and the abundance, prevalence, species richness, diversity, and total number of parasites in the infracommunities of Sebastes capensis was analyzed. Nine helminth species were obtained from 180 red rockfish captured off Coquimbo Bay, Northern Chile. These included the digeneans Pseudopecoelus sp., Diphtherostomum sp., Derogenes sp., Podocotyloides sp., and Lecithochirium sp., the acanthocephalan Corynosoma sp., and the nematodes Ascarophis sebastodis, Hysterothylacium sp., and Anisakis sp. The abundances of Pseudopecoelus sp. and Anisakis sp. were significantly and positively correlated with the size of S. capensis, while Corynosoma sp. correlated negatively with host size. Only prevalence of Anisakis sp. increased with host size. The number of parasite individuals increased significantly with size of S. capensis. However, species richness and diversity of the infracommunities was not affected by host size. These results suggest that red rockfish >18 cm do not undergo significant ontogenetic changes in their diet. Host sex did not seem to affect abundance and prevalence of infections. The presence of Derogenes sp. and Podocotyloides sp. are new records of digeneans for S. capensis.