Though guitarfish are common bycatch and have an economical value in the Mediterranean Sea, there is still limited knowledge on blackchin guitarfishs, Glaucostegus cemiculus, their presence or any biological feature, with specific regard to those that inhabit the eastern Mediterranean coasts of Turkey. To explore this information gap, bio-ecological features, which are investigated in terms of stomach contents and reproduction, were examined from individuals obtained from Izmir Bay. A total of 122 individuals caught as by-catch were collected monthly between: July 2015-June 2016. Crustaceans were found to be the main prey item in their diets. Maturity stages were mainly immature, with the exception of two individuals: an immature 2-developing female and mature 3b-active male. Knowledge retrieved from present studies on bio-ecological features contributes to closing the current information gap on endangered blackchin guitarfish in the eastern Aegean Sea. Such studies also provide a platform for essential discussion on the various ways in which effective r monitoring strategies for the species could be implemented and managed; particularly in the Turkish coast of the eastern Mediterranean. (C) 2019 Elsevier B.V. All rights reserved.