From Atlantic to Greece. The Case of Nasal Mite in Mediterranean Monk Seal

Abstract

Marine mammal dispersion and heterogeneity is worldwide and depends on the geographical area. Some species live isolated, while others can be found all over the oceans. This isolation can possibly be the case of different kinds of diseases among them as in each geographical area different pathogens prevail. Pinnipeds seem to be the main host of nasal mites, while gray seals, especially in Atlantic waters, seem to develop vulnerability to the species Halarachne halichoeri. A Mediterranean monk seal was found dead in the Pagasetic Gulf in Greece by professional fishermen. Anatomy in the cardiorespiratory system revealed the presence of parasitic individuals in both lungs. Internal Transcribed Spacer 1 (ITS1) and 5.8S ribosomal RNA gene sequencing results of the examined parasites showed 91.8% similarity to the species Halarachne halichoeri as the overlap reaches 95%. This species lives in the respiratory system of flippers mainly in the Baltic Sea and the European Atlantic coast. It has not been observed in the Mediterranean to date and it is very likely that this also applies to the parasite under study. Although the species found in the Mediterranean seal's respiratory system has not been identified, speculation about its origin and the pathology it causes has been linked to Halarachne halichoeri. The most probable scenarios are the entry of the seal from the Atlantic Ocean to the Mediterranean, the entry of another seal species, host of Halarachne halichoeri, from the Atlantic to the Mediterranean and its contact with the person under study, as well as the passage of the parasite to the Mediterranean, as in the larval phase it may live outside its host, but these scenarios are assumed, since to date there are no recordings.