Occurrence of Halarachne halichoeri in Mirounga leonina on the Coast of Argentina (Parasitiformes, Mesostigmata, Halarachnidae) with a Review of Worldwide Records

Abstract

Halarachne halichoeri mites are respiratory parasites of pinnipeds that have been recorded from different locations around the world, but not from the coast of Argentina. In this study, the presence of H. halichoeri on the southern elephant seal, Mirounga leonina, is documented for the first time in the Argentinean mainland, specifically in the Paraná River on the Buenos Aires coast. A total of 4130 adult and immature mites (90.4% larvae, 0% nymphs, 9.2% females and 0.4% males) were collected from the nose and nasopharyngeal cavity of a stranded juvenile male during a necropsy. The species was identified using scanning electron microscopy (SEM) and stereomicroscope photography, and the morphological characteristics of the females and males are shown. Also, images of the male are shown for the first time, with observable details of traits. We also propose a method for simple sex recognition. Finally, we provide a revision of global records of geographic distribution of H. halichoeri in wild marine mammals. The present record of occurrence of the species H. halichoeri in Argentina expands our knowledge about the distribution area known to date for this species of marine parasite.