FIRST OBSERVATION OF THE EMBRYOS OF SPINY BUTTERFLY RAY, GYMNURA ALTAVELA (LINNAEUS, 1758) (CHONDRICHTHYES: GYMNURIDAE) FROM EASTERN MEDITERRANEAN, A SPECIES CRITICALLY ENDANGERED

摘要

In this study, the morphometric identification of a pregnant Gymnura aitacela and its three embryos, which is incidentally captured by fishermen with trammel nets on April 2, 2018, in the Gulf of Izmir in the Aegean Sea, Turkey, was carried out. In the study, 18 morphometric measurements of the pregnant specimen and three embryos were compared with each other. The disc width (DW), total length (TL), and weight (W) of the pregnant specimen were 135.5 cm, 90.0 cm, and 20.200 g, respectively. Of the embryos obtained from the right uterus of the female specimen, 1 was male and 2 were female. The disc width of the embryos varied between 28.6 cm and 30.9 cm, total length of the embryos varied between 22.2 and 22.9 cm, and the weight of the embryos varied between 289.51 and 296.13 g. The results obtained with the morphometric measurements were evaluated using discriminant analysis and the results revealed that female and male embryos and the adult specimen had a 100% discrimination ability.