SCRS/2008/191 PRELIMINARY ANALYSIS OF REPRODUCTIVE BIOLOGY OF PELAGIC STINGRAY, Pteroplatytrygon violacea IN SOUTHWESTERN ATLANTIC Dráusio P. Véras 1 ; Ilka S. L. Branco 2 ; Fábio H. V. Hazin 2 ; Catarina Wor 2 ; Mariana Travassos Tolotti 2 SUMMARY The pelagic stingray, Pteroplatytrygon violacea, is the only member of the Dasyatidae family with an entirely pelagic behavior. In the present work a total of 367 specimens, 137 females (37.3%) and 230 males (62.7%), were examined, with a view to study their reproductive biology. The specimens were collected between October 2005 and January 2008, by observers onboard of Brazilian commercial longliners. The disc width (DW) ranged from 28.0 to 63.2 cm for females and from 34.0 to 59.6 for males. Females were classified as immature (n= 30; 22.4%); maturing (n= 41; 30.6%); pre-ovulatory (n= 25; 18.7%); pregnant in early gestation (n= 14; 10.4%); pregnant in mid gestation (n= 8; 6.0%); pregnant full term (n= 2; 1.5%); postpartum (n= 4; 3.0%); and resting (n= 10; 7.5%). For the 24 (17.9%) pregnant females the DW ranged between 46.0 and 60.8 cm. The monthly distribution of the reproductive stages does not indicate any clear seasonality for the reproductive cycle of the species. Ovarian vitellogenesis seems to happen simultaneously with gestation, indicating that females are ready to ovulate close after parturition. Size at first sexual maturity was estimated at around 45 cm DW for females, and at or below 34 cm for males, since all sampled specimens were equal or larger than this size and were all already mature. KEYWORDS elasmobranches, bycatch, biology 1 PhD. Student – Universidade Federal de Pernambuco/Departamento de Oceanografia, Recife-PE, Brasil (drausioveras@hotmail.com) 2 Universidade Federal Rural de Pernambuco/Departamento de Pesca e Aqüicultura, Recife- PE, Brasil