Exploring the elusive deep‐sea sharpnose sevengill shark (Heptranchias perlo) in the Adriatic Sea: Novel records, health assessments and conservation implications

Abstract

The sharpnose sevengill shark (Heptranchias perlo) is a rare and poorly understood deep‐sea species, with only a few records in the Adriatic Sea over the last two centuries and a significant gap in sightings. Throughout 2023, three new records are documented in the southernmost Adriatic Sea, found at depths ranging from 391 to 452 m off Vlorë. This study marks the first comprehensive health examination of a deep‐sea shark, investigating potential trauma and injuries resulting from trawling. It encompasses pathological and histopathological examinations, supplemented by magnetic resonance imaging (MRI). The research highlights alarming post‐capture mortality rates in this data deficient species, discusses further conservation implications, and proposes protective measures for the species. Beyond addressing critical knowledge gaps, this study advocates for collaborative efforts with local fishermen to establish long‐term monitoring and obtain data on the frequency and abundance of elusive species.