Abstract

A total of 106 specimens of the big eye grenadier, Macrourus holotrachys, were obtained from 2015 to 2019 as bycatch from the artisanal fishery for Patagonian toothfish (Dissostichus eleginoides) at depths between 1000 and 2200 m in Northern Chile (app. 22 degrees S 70 degrees W). All individuals were examined for their endoparasite fauna and diets. A total of twenty-five parasite taxa (e.g. fifteen Digenea, six Nematoda, three Cestoda, and one Acan-thocephala) were found. Twenty taxa were found as adults, four species were found in the larval stage, and one species was found in both the larval and adult stages. Hysterothylacium sp. (Nematoda); Trypanorhyncha gen. sp. (Cestoda); and Monorchiinae gen. sp. (Digenea) were the predominant species, which had a prevalence of 64.2%, 42.5% and 31.1%, respectively. The diet of M. holotrachys included thirteen item-prey, Decapoda and Ophiuridae showed the highest frequency of occurrence (66.3% and 43.3% respectively). A multivariate canonical correspondence analysis (CCA) showed that the association between endoparasites and diet of M. holotrachys explained 45.1% of the total variance. The detected parasite community consisted of parasites linked to benthic, benthopelagic and pelagic environments. This suggests the role of M. holotrachys as a predator of communities close to the seabed but also within the water column, performing vertical and horizontal migrations in the South Eastern Pacific Ocean.