Geographic variation in composition of metazoan parasite infracommunities in Galaxias maculatus Jenyns 1842 (Osmeriformes: Galaxiidae) in southern Chile (38-47° S)

Galaxias maculatusis an abundant freshwater fish species in Chilean continental waters where it plays important ecological functions, yet few parasitological records of this species exist in Chile and all of them cover a very limited geographic range. The objective of this study was to assess large scale geographic variation in composition of parasite infracommunities ofGalaxias maculatus.Specifically, parasite infracommunities of this species were compared among 11 locations across 9 degrees of latitude and 3 ecosystem types (lake, river and estuary). Most taxa found had been previously reported in Chile and Argentina. However, this is the first report forTylodelphyssp. in this host in Chile. Furthermore, the cranial parasiteTylodelphyssp. had the highest overall prevalence and abundance compared to other parasite species. Despite the fact that the abundance ofTylodelphyssp. was not significantly correlated with Fulton’s condition factor of fish, infected fish seem to have a better body condition compared to uninfected ones. The most important source of variation in composition of infracommunities was the sampling location. Furthermore, fish from lakes have a different composition of parasite infracommunities mainly due to higher abundances ofTylodelphyssp.