Morphological and Molecular Characterization of Anisakid Nematode Larvae (Nematoda: Anisakidae) in the Black Cusk eel Genypterus maculatus from the Southeastern Pacific Ocean off Peru

The back cusk eel, Genypterus maculatus (Tschudi, 1846), (Ophiidiformes: Ophiididae) is one of the benthic-demersal fish usually consumed in northern Peru. Here, we identified the third stage (L3) Anisakidae sampled from 29 specimens of G. maculatus captured off the south American Pacific coast, Lambayeque Region, Peru. A total of 20 anisakid nematode larvae were collected on the visceral surface and divided morphologically into three types (Type I-III). These larvae were identified by mtDNA Cox2 sequences analysis, which indicated that corresponded to Anisakis pegreffii Campana-Rouget and Biocca, 1955, Skrjabinisakis physeteris (Baylis, 1923) and S. brevispiculata (Dollfus, 1966) Safonova, Voronova, and Vainutis, 2021, respectively. This is the first record of S. brevispiculata in Peru. The results obtained in this study provide knowledge on the diversity and distribution of Anisakis Dujardin, 1845 and Skrjabinisakis Mozgovoi, 1951, species in the south American Pacific waters and their relevance for public health. In addition, we suggest that combined use of molecular and morphological approaches is needed to characterize L3 anisakid larvae.