Diet of the Deep-Sea Shark Galeus melastomus Rafinesque, 1810, in the Mediterranean Sea: What We Know and What We Should Know

We reviewed literature on the diet of the Galeus melastomus Rafinesque, 1810, from theMediterranean Sea. Specific keywords ("Galeus melastomus diet", "feeding habits", "trophic position","biology", "deep environment adaptation") in the principal data sources, such as Web of Science,PubMed, and Google Scholar were used. Seventeen studies conducted on the diet and trophicposition of G. melastomus have been considered for Mediterranean Sea regions. The feeding habitshave been analyzed in many areas of the western basin; instead, for the Tyrrhenian, Adriatic, andcentral Mediterranean Seas, information is outdated and fragmentary. In all investigated sub areas,the data showed that G. melastomus is an opportunistic demersal supra benthic predator, benthicfeeder, and scavenger, that adapts its diet to the seasonal and geographical fluctuations of theprey availability. It occupies a generalist niche showing individual specialization. In all reviewedMediterranean sub areas, the most important prey groups were crustaceans, cephalopods, andteleost fishes. Taxa percentage in its diet composition can vary depending on different habitats withontogenetic development of individuals, depth (that is correlated with the ontogenetic development),seasonal availability, and distribution of different prey groups. Widening knowledge of G. melastomusfeeding habits is a fundamental tool for better understand meso and bathy-pelagic ecosystems.