Endohelminth parasite communities of Clinocottus analis (Perciformes: Cottidae) and Girella nigricans (Centrarchiformes: Girellidae) in the rocky intertidal zone of Punta Morro, Baja California, Mexico.

The rocky intertidal fish species Clinocottus analis and Girella nigricans from Punta Morro, Baja California, Mexico, were examined for endohelminth parasites. In C. analis, three helminth species were identified: the adult trematodes Opecoelus adsphaericus and Schikhobalotrema girellae, and the adult nematode Ascarophis morronei. In G. nigricans, five helminth taxa were identified: the adult trematodes O. adsphaericus, S. girellae and Opisthadena cheni, as well as the metacercaria of Prosorhynchoides sp. and the cystacanth of Floridosentis sp. Schikhobalotrema girellae is reported for the first time in C. analis, while Prosorhynchoides sp. and Floridosentis sp. are also new records for G. nigricans. At the infracommunity level, the mean species richness was very low (C. analis = 0.57 ± 0.532; G. nigricans = 1.028 ± 0.774), and numerically dominated by O. adsphaericus. The component communities are depauperate and strongly dominated by O. adsphaericus. Helminth parasite communities differed in the number of parasite taxa between the two host species, sharing two of the six parasite taxa (i.e., O. adsphaericus and S. girellae). Based on the gastrointestinal contents observed in this study for the two host species, their feeding habits likely influence the composition of helminth parasite communities.