Stomach contents of the pelagic stingray (Pteroplatytrygon violacea) (elasmobranchii: dasyatidae) from the tropical atlantic

Abstract

Universidade Federal Rural de Pernambuco - LEMAR/DEPAq (Av. Dom Manuel de Medeiros s/n, Dois Irmaos, 52171-900 Recife, PE, Brasil) E-mail: p.travassos@depaq.ufrpe.br; mari.trrr@gmail.com The pelagic stingray Pteroplatytrygon violacea (Bonaparte, 1832) is the only pelagic dasyatid ray occurring in tropical and subtropical waters of the Atlantic, Indian and Pacific Oceans (BIGELOW; SCHROEDER, 1953; MOLLET, 2002; ELLIS, 2007). This poorly known species was originally described from the Mediterranean Sea, and was first reported from the Atlantic by Bigelow & Schroeder (1962). The species has no commercial value, but is fairly abundant off the Southeastern United States representing about 2.5% in number of the catches by pelagic longlines between 1992-2000 (BEERKIRSHER et al., 2004). The first record in southern Brazilian waters was reported by Sadowski; Amorim (1977) and Mazzoleni; Schwingel (2002) subsequently recorded the pelagic stingray as a bycatch species regularly caught by tuna longliners off southern Brazil. Menni et al. (1995) reported on the presence of the pelagic stingray in northeastern Brazilian waters. Although the pelagic stingray is caught regularly by tuna longliners operating along the Brazilian coast, few biological data are available on the species. In this context, the stomach contents of the pelagic stingray were analyzed to provide more specific information on its feeding habits in the southwestern equatorial Atlantic Ocean. The sampled area was located between 40o- 25oW and 5oN-20oS (Fig. 1). All specimens were caught by the Research Vessel Riobaldo (CEPENE-IBAMA), in the years 1993, 1994 and 1995 through the Ecotuna Project, and by the Brazilian tuna longline fleet, in the years 2005 and 2006 (SEAP, Onboard Observer Program), in waters of 2000 to 5000 m local depth, with hook depth between 50 and 250 m along the longline. The specimens were stored on ice onboard, and at the laboratory, they were sexed and had their disc width measured to the nearest centimeter.