Atypical characteristics in blackmouth catshark, Galeus melastomus (Chondrichthyes: Scyliorhinidae) from the Algerian coast (southern Mediterranean Sea)

The authors report in the present paper the capture of an abnormal specimen of the blackmouth catshark Galeus melastomus Rafinesque, 1810 from the central coast of Algeria (southern Mediterranean Sea). The specimen was a sub–mature female having 478 mm in total length (TL) and weighing 265 g in total body weight (TBW). The specimen displayed a severe atrophy of the right clasper and a poor development of the right pelvic fin. These abnomalities are compared with other similar patterns reported in elasmobranch. The origin of the abnormalities remains questionnable, due to unfavourable environmental conditions (action of pollutants) or to endogenous origin or genetic during embryonic development.