Seasonality of Reproduction and Embryonic Growth of Spiny Dogfish (Squalus acanthias L., 1758) in the Eastern Black Sea

Authors: SEFA AYHAN DEMİRHAN, KADİR SEYHAN

Abstract: The seasonality of reproduction and embryonic development of spiny dogfish (Squalus acanthias) sampled from the Eastern Black Sea were studied. The gestation period of spiny dogfish, starting in August, September and October, takes around 23-24 months. Fertilized females were caught at a depth of 30-45 m in July and August. Females with full-term pups and empty uteri were found at 50-60 m depth, where the temperature was 10 °C. Lengths of pups at birth were around 28-29 cm, whereas their weights ranged from 68 to 78 g. The models of embryonic growth and development of ova were described as TL_e = 0.8124 – 0.334 x mo + 0.1289 x mo^2 - 0.03 x mo^3 (r = 0.92) and D_o = 0.7364 – 0.1503 x mo + 0.0221 x mo^2 - 0.004 x mo^3 (r = 0.94), respectively.

Keywords: Reproduction, embryo, Squalus acanthias, Black Sea

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