Sexual maturity and fecundity of Scyliorhinus canicula (Linnaeus, 1758) in the Aegean Sea

Abstract

A total of 325 small-spotted catsharks, Scyliorhinus canicula, ranging from 263 to 488 mm in total length (TL) and from 62 to 395 g in round weight (RW), were sampled from trawl catches in the Aegean Sea during the two-year period 2005–2007. The overall ratio of males to females was 1.06:1, and of the specimens almost 60% were mature. The size of mature males and females ranged between 371–488 mm and 364–467 mm in total length, respectively, while total length at 50% maturity was estimated at 396 mm for males and 399 mm for females. Ovary weight varied from 0.1 to 25.4 g and maximum oocyte diameter was 18 mm. Gonadosomatic indices ranged from 0.13 to 9.77 in female fish and from 0.25 to 6.36 in male fish, showing significant seasonal changes only in females (p-value < 0.05). Ovarian fecundity reached a maximum of 18 ripe oocytes in the ovary of a 460 mm TL female. Only one pair of egg cases was found in each one of the 30 adult females examined.

Keywords:

• Scyliorhinus canicula
• sexual maturity
• Mediterranean Sea

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

The present study was funded through the Operational Programme for Education and Initial Vocational Training (O.P. ‘Education’) in the framework of the project ‘Pythagoras II – Support of University Research Groups with 75% from European Social Funds and 25% from National Funds.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark