The blackmouth catshark, Galeus melastomus presents a wide Atlanto-Mediterranean distribution, and is commonly captured off the Languedocian coast (southern France, northern Mediterranean). The males and females sexually matured between 510–550 mm and 520–610 mm total length (TL), respectively. The largest male and the largest female were 620 mm and 640 mm TL, respectively. There was a significant relationship of total liver mass vs TL between males and females. The diameter of the largest yolky oocytes ranged from 15 to 18 mm (16.5 ± 2.7). Production of egg cases was observed throughout the year, except in September. Egg cases had between 36 and 50 mm (mean: 45.3 mm ± 3.9) in length without horns, and between 14 and 21 mm (18.2 mm ± 1.4) in width. Fecundity remained difficult to assess; an estimation based on production of egg cases enabled us to consider 93 egg cases per year as a maximum.
