Occurrence of Anisakis pegreffii (Nematoda: Anisakidae) larvae in Larimus pacificus (Eupercaria: Sciaenidae) from northern Peruvian waters.

Anisakis pegreffii Campana-Rouget & Biocca, 1955 (Nematoda: Anisakidae) is a zoonotic nematode of increasing public health concern, particularly in regions where raw or lightly processed fish is traditionally consumed. This study provides the first molecular evidence of A. pegreffii infection in the Pacific drum, Larimus pacificus Jordan & Bollman, 1890 (Eupercaria: Sciaenidae), a neritic fish species endemic to the eastern Pacific and frequently sold in local markets along the northern Peruvian coast. A total of 78 specimens of L. pacificus were collected from northern Peruvian waters and examined for anisakid larvae. Seventy-six third-stage larvae (L3) were recovered from the viscera and muscle tissues of 46.15% of hosts. The mean intensity was 1.5 ± 0.69 and the mean abundance was 0.72 ± 0.91. DNA was extracted from representative larvae and the mitochondrial cytochrome c oxidase subunit II (cox2) gene was amplified and sequenced. All sequences showed high similarity (99.19-100%) to reference sequences of A. pegreffii in GenBank (OR192867, OR192867, MZ546440, DQ116428), confirming the species identity. Phylogenetic analyses using Bayesian inference and maximum likelihood approaches grouped Peruvian isolates within a strongly supported clade of A. pegreffii, together with sequences from Delphinus delphis Linnaeus, 1758 (Cetartiodactyla: Delphinidae) from the Northeast Atlantic Ocean and marine fish from the southeastern Pacific. Genetic distances among Peruvian sequences and reference specimens were low (0.37-1.85%), indicating limited intraspecific variation. These findings constitute the first record of A. pegreffii en L. pacificus and underscore the importance of continued surveillance and food safety measures in artisanal fisheries.