Unusual shallow inshore records of Cornish blackfish Schedophilus medusophagus (Stromateoidei: Centrolophidae) from Galician waters (NW Spain)

摘要

Three shallow inshore records of Cornish blackfish Schedophilus medusophagus from Galician waters (NW Spain) are reported. S. medusophagus is a relatively rare mesopelagic species in the NE Atlantic. Adult specimens are mainly found in medium-depth waters (300-900 m). Their presence in shallower coastal waters is very unusual. An historical review of North Atlantic shallow inshore records was made. Reproductive and stomach content analyses were investigated and related to two proposed inshore migration hypotheses. Resulting from these investigations, the first description of gametogenesis and gonadal development organization of this species is presented. Ovary development was found to be group-synchronous, with a highly synchronous population of larger follicles. Testicular tissue was found to be lobular type. Since no conclusive evidence was found to support either of the two proposed hypotheses an additional hypothesis related to increasing sea water temperatures was proposed.