Molecular and Morphological Identifications of Anisakis Dujardin, 1845 (Nematoda: Anisakidae) from a Rare Deraniyagala’s Beaked Whale (Mesoplodon hotaula Deraniyagala, 1963) and Blainville’s Beaked Whale (Mesoplodon densirostris Blainville, 1817) Stranded Off Southern Philippines

Abstract

Beaked whales are among the definitive host of the parasitic worm Anisakis Dujardin, 1845. In this study, molecular [using ribosomal internal transcribed spacer (ITS) region and mitochondrial DNA cytochrome c oxidase subunit 2 gene (mtDNA COX2)] and morphological (light microscopy and scanning electron microscopy) identifications of Anisakis from a rare Deraniyagala’s beaked whale Mesoplodon hotaula Deraniyagala, 1963 and Blainville’s beaked whale Mesoplodon densirostris Blainville, 1817 stranded in Davao Gulf, Southern Philippines are presented. Results conclusively revealed that the worm samples were A. ziphidarum, representing an additional geographical record for the species along the West Pacific region and a first record examined from the rare Deraniyagala’s beaked whale, representing a new host record for the species. Interestingly, both molecular and morphological data further revealed that the worms collected from Deraniyagala’s beaked whale consisted of two subgroups under the A. ziphidarum clade suggesting possible cryptic species, one of which is closely related to the Atlantic species while the other could be a local variant specific to the West Pacific.