Host-Parasite Relationships Between Dolops spp. (Crustacea: Branchiura) and Freshwater Fish from the Neotropical Region

Purpose: Ectoparasitic crustaceans can harm their hosts due how they attach to and feed on their hosts. Consequently, host fish with high infestation intensities show reduced survival rates, which can negatively affect host populations. Understanding host-parasite relationships and monitoring parasitic infestations in wild fish can provide epidemiological information and help avoid ecological damage. This study aimed to document and characterize the occurrence of ectoparasitic crustaceans in Serrasalmus maculatus and conducted a systematic bibliographic review of fish species previously reported as hosts for the parasite taxa found in this study. Methods: Fifty specimens of S. maculatus were collected in 2018. For each parasite species detected, the attribute prevalence (P), mean intensity of infestation (MII), and mean abundance (MA) were calculated. In addition, the main databases were reviewed to document the fish species reported as hosts of the branchiurans in this study. Results: A total of 195 specimens of Dolops carvalhoi (P = 72%) and 121 of Dolops bidentata (P = 58%) were identified. Here, we report the first record of D. bidentata in the Paraná River and the first record of a D. carvalhoi and S. maculatus interaction. This review shows that D. bidentata and D. carvalhoi have low parasite specificity. Conclusion: The association between Dolops spp. and Serrasalmus maculatus is epidemiologically important because these branchiurans are potential vectors for Epistylis spp. Serrasalmus maculatus is attracted to cage fish farm areas and can transmit parasites to farmed fish. Our study contributes to the knowledge of host-parasite specificity and geographical distribution of this poorly studied ectoparasitic group.