Molecular characterization of Maccallumtrema xiphiados (Trematoda: Azygiida) and Molicola sp. (Cestoda: Trypanorhyncha) infecting commercial frozen slices of Atlantic swordfish.

Abstract

Muscle gross lesions, associated to parasites, were routinely found during self-inspection in a Spanish fish plant processing Atlantic swordfish. To determine the taxonomic status of these parasites, molecular analysis was performed based on 18S, ITS1, 5.8S, ITS2 and 28S rDNA sequences, obtaining a consensus sequences of 4581 bp for the cestode and 4200 bp for the trematode. Taxonomic affiliation was determined by phylogenetic analysis of combined SSU + LSU rDNA regions using maximum likelihood models. Molecular characterization allows us to identify the trematode Maccallumtrema xiphiados and the cestode Molicola sp. infecting the musculature of the Atlantic swordfish. Both parasites are responsible of significant economic loss to fish industry due to commercial rejection of parasitized products.