HOTSPOT E DINAMICA SPAZIALE DEI GIOVANILI DELLO SQUALO BOCCANERA (GALEUS MELASTOMUS RAFINESQUE, 1810) NEL TIRRENO CENTRO-MERIDIONALE

HOTSPOT AND SPATIAL DYNAMICS OF THE JUVENILES OF THE BLACKMOUTH CATSHARK (GALEUS MELASTOMUS RAFINESQUE, 1810) IN THE CENTRAL-SOUTHERN TYRRHENIAN SEA

Abstract

Galeus melastomus (Rafinesque, 1810) is a demersal species widely distributed in the Mediterranean Sea, with the exception of the central and northern Adriatic regions. Despite its widespread distribution, knowledge of its spatial and temporal distribution remains limited, particularly in the central and southern Tyrrhenian Sea. This study analyses the juvenile component of G. melastomus, estimating its abundance and distribution pattern. The consistent presence of recruits in all sampling campaigns suggests prolonged or continuous recruitment, consistent with previous observations on the species' reproduction. The Recruit Density Index shows a decreasing trend, suggesting possible recruitment challenges related to environmental factors and anthropogenic pressures, such as trawling and deep-sea longlining. The 201–500 m bathymetric layer is characterized by a high concentration of juveniles and hotspots, suggesting favourable conditions for survival and trophic resources. However, the analysis of the persistence of hotspots highlights a dynamic distribution, with few stable areas over time.