Diversity of endohelminth parasites of fish from Sali-Dulce River tributary (Tucumán province, Northwestern Argentina)

Abstract Purpose Medina-Salas River is a tributary of Sali-Dulce endorheic system, one of the most important basins of Northwester Argentina. Despite, many endemic fish species can be found in this endorheic system, and its ichthyological diversity is affected by anthropogenic activities, the diversity of endohelminth parasite of fish in this river remains unexplored. This study aimed to analyse the structure and composition of endohelminth communities of fish species from lower sector Medina-Salas River. Methods Fish belonging to seven species ( Bryconamericus iheringii , Jenynsia tucumana , J. lineata , Trichomycterus corduvensis , T. alterus , T. spegazzinii , and Heptapterus qenqo ) were examined for endohelminth parasites. Ecological analyses were performed at the component community and infracommunity levels. Results A total of 1269 endoparasites belonging to six taxa (5 Nematoda and 1 Cestoda) were found in the intestine or abdominal cavity from a total of 951 fishes screened. Contracaecum sp. was the only taxon found in the larval stage. The helminth taxon that displayed the highest prevalence, mean intensity and mean abundance was the nematode Cucullanus pinnai of H. qenqo . Most taxa of parasitic helminth exhibit the typical aggregated pattern of distribution within host populations. All component communities presented a low richness and diversity values. Jenynsia tucumana showed the most diverse helminth component community. Conclusion This study is the first comprehensive ecological survey on the diversity of endohelminth fauna of freshwater fish species from Northwest Argentina, presenting six new host records contributing to the knowledge of the real patterns of helminth parasites diversity from Neotropical fish.