Metazoan parasite community of Hoplias malabaricus (Characiformes, Erythrinidae) in a stream of Caatinga domain, Brazil.

We purpose to describe and characterize the structure of the parasitic community of H. malabaricus in a stream from Caatinga domain, Ceará state, Brazil. A total of 42 specimens of H. malabaricus have been collected between December 2018 and August 2019, in which, 34 specimens were parasitized by at least one parasite. A total of 1,872 parasites were recovered, of which, 157 were Urocleidoides cuiabai (prevalence = 50%), 268 Urocleidodes brasiliensis (prevalence = 71.43%), 98 Dactylogyridae gen. sp. (prevalence = 14.29%), 401 Diplostomidae gen. sp. (prevalence = 4.76%), 183 Spiroxys sp. (prevalence = 42.86%) and 765 Pindapixara tarira (prevalence = 9.52%). The respective parasite species of H. malabaricus showed a pattern of overdispersion (or aggregation) typical of the parasitehost systems, corroborating with previous studies of parasitic communities of freshwater fish in Brazil. A positive and significant correlation between the host size and abundance of U. brasiliensis was verified. The ontogeny of fish can influence the parasitic load, some larger hosts tend to host larger quantities of parasites. The parasitic levels can vary with the host sex due to the differences in the ecological and physiological interactions between male and female. However, the host sex did not show influences in the prevalence and parasitic burden. All parasite taxa in this study have not yet been reported in the Carás stream, Caatinga domain. This finding extends the geographical distribution of this parasite species, furthermore, contributing to the knowledge of the biodiversity of fish parasites in the Neotropical region.