Distribution and population structure of the pelagic stingray,
The present study analyses the spatial and temporal distribution of the pelagic stingray (Pteroplatytrygon violacea) in the south-western Atlantic Ocean, based on data collected between April 1998 and March 2006 by the National Observers Program of the Uruguayan Tuna Fleet. During this period, data were recorded on 51 commercial fishing trips, in which a total of 2 306 851 hooks were set and 2740 stingrays captured. Of these, the sex was determined for 1329 individuals and the size for 944. The average disc width was 47 ± 8 cm (range: 24–82 cm) for females and 44 ± 5 cm (range: 28–84 cm) for males. The results indicate that the species seems to prefer warm temperate and tropical waters. There were no capture records in waters at <15.3 °C. The data collected suggest a mating season in late spring with a gestation period of 2 to 4 months and births occurring during late summer and early autumn. The increasing bycatch of this ovoviviparous species in pelagic longline fisheries, with an unknown survival rate after discard, coupled to its low reproductive potential, call for better monitoring in order to accurately determine its current conservation status.
Auteurs du document :
Rodrigo Forselledo, Maite Pons, Philip Miller, Andrés Domingo