First Detection of Photobacterium spp. in Acute Hemorrhagic Septicemia from the Nursehound Shark Scyliorhinus stellaris

Abstract

The nursehound Scyliorhinus stellaris is a threatened shark species and its population in the Mediterranean Sea is declining. Programs for captive breeding and repopulation in marine protected areas (MPA) are being carried out. Unfortunately, pathogens may hinder conservation plans for this species. An impactful disease of marine animals, caused by the bacteria Photobacterium damselae, has been detected with increased frequency in recent decades in both farmed and marine animals. The aim of this work was to determine the cause of a disease outbreak in eight captive nursehounds that died after 18 months of captivity. Gross necropsy observations were indicative of a presumptive diagnosis of hemorrhagic septicemia. Histological and molecular techniques were performed, to diagnose the etiological agents that could be involved in their mortality. Phylogenetic analysis indicated the presence of P. damselae, identified as subsp. damselae by PCR-duplex, and Photobacterium swingsii in the analyzed captive nursehound Scyliorhinus stellaris.