Vertical movements of the southern stingray, Dasyatis americana (Hildebrand & Schroeder, 1928) in the Biological Reserve of the Rocas Atoll, Brazil
The southern stingray, Dasyatis americana, one of the most common species of rays of the family Dasyatidae, is distributed in tropical and subtropical waters of the western Atlantic Ocean. In Brazil, it occurs especially in the northeast coast, being usually sighted in Fernando de Noronha Archipelago and in the Rocas Atoll. The present research sought to elucidate the pattern of vertical movements of the D. americana inside the Rocas Atoll and in its surroundings, through the use of satellite electronic transmitters PSAT (Pop-up Satellite Archival Tags), as well as to understand the role of Rocas Atoll in the conservation of this species. The vertical distribution of depth and temperature were obtained from two adult female stingrays, identified as Ray I and Ray II, measuring approximately 95 and 108 cm disc wide respectively. The results indicated a strong preference for both specimens for the shallow and warm waters of the Rocas Atoll. Ray I and Ray II remained 91.4% and 86.3% of the monitoring period, respectively, in warm waters, at temperatures >28°C and up to 5 m in depth. The results show that areas with shallow waters constitute one of the essential habitats for the species in Rocas Atoll, with a likely occurrence of site fidelity.