REPRODUCTIVE BIOLOGY OF THE COMMON EAGLE RAY MYLIOBATIS AQUILA (CHONDRICHTHYES: MYLIOBATIDAE) FROM THE COAST OF LANGUEDOC (SOUTHERN FRANCE, NORTHERN MEDITERRANEAN)

Investigations conducted off the coast of Languedoc (southern France, northern Mediterranean) during 14 years show that common eagle rays Myliobatis aquila (Linnaeus, 1758) were caught especially from August to October. The smallest male and female adults were 500 mm and 730 mm disc width (DW), respectively, and weighed 2000 g and 6100 g. The largest male and the largest female were 720 mm and 1140 mm DW, respectively and weighed 5250 g and 29400 g, respectively. There was a significant relationship of total mass versus DW between males and females. Diameter of the largest yolky oocytes ranged from 26 to 32 mm, number of yolky oocytes counted in five females ranged between 8 and 10. Fertilized eggs were enveloped in a diaphanous capsule. Each capsule containing six eggs weighing between 4.5 and 5.3 g (mean: 4.9 plus or minus 0.9). Breeding period probably occurred from August to September. The common eagle ray probably reproduced in alternate year, and embryonic development did not exceed one year. Ovarian fecundity and uterine fecundity were rather low, both between 8 and 12.