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Near term embryos and gravid females of Lusitanian cownose ray (Rhinoptera marginata) in Mersin Bay, the eastern Mediterranean Sea
Batoid chondrichthians are vulnerable to commercial fisheries even though they are often not targeted. A greater understanding of their reproductive biology is important for facilitating their conservation. In February 2013, 89 female and 40 male Lusitanian cownose ray (Rhinoptera marginata) specimens were accidentally caught in Mersin Bay in the eastern Mediterranean Sea. Thirty-sixth fish were gravid, each bearing one embryo. Of the remaining females, 39 were sexually mature but nongravid and 14 were immature. There were 28 mature and 12 immature males. The average disc width (DW) of both mature females (80.2 cm) and males (74.2 cm) were significantly higher than those of the immature females (60.7 cm) and males (60.3 cm). The DW and total weight (TW) ranged between 55.7-98.2 cm and 1802-13600 g for all rays. The DW and TW measured for all 16 female and 20 male embryos were between 15.6-29.2 cm and 57-281 g. Such a large single haul sample, including many gravid specimens and mature males, indicates a schooling formation at capture. The location in Mersin Bay near the estuaries of Tarsus and Seyhan rivers, and its relative closeness to the sampling location of a previously reported neonate, suggests that this region may be a nursery area for Lusitanian cownose rays in the eastern Mediterranean.
MF17356 Accepted 20 February 2018
© CSIRO 2018