Biologia reprodutiva da raia dasyatis guttata (Bloch & Schneider, 1801) (Myliobatiformes: Dasyatidae) no litoral do Pará

• Autor(a) principal: Palmeira, Ana Rita Onodera
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/tede/4145
• topic: Dasyatidae; Norte Brasil; Maturação sexual; Ciclo reprodutivo; Dasyatidae; Northern Brazil; Sexual maturation; Reproductive cycle; CIENCIAS BIOLOGICAS::ZOOLOGIA

Camara beach is located in an Amazonian estuary in Pará State, northern Brazil, where fishing is a traditional activity and there is capture of several species of rays. The longnose stingray, Dasyatis guttata, is the most common in the catches, and as regional information on its biology is scarce, this study aimed to investigate aspects of reproductive biology of D. guttata and to determine its reproductive cycle in this area. Monthly samplings were performed from April 2011 to March 2012, through monitoring of artisanal fisheries with longline and trapping fence barriers ( currais ). A total of 81 specimens of D. guttata were collected, and the class with the largest number of individuals sampled was 100-200 mm disc width (DW), comprised of neonates and young. The presence of neonates observed throughout the year indicates Camara beach as a primary nursery area for this species. The presence of males is restricted to few months of the year and indicates a tendency to sexual segregation. The monthly variation in the abundance of individuals of D. guttata followed the variation of temperature and salinity number of specimens, suggesting seasonal migration. The disc width class in which 50% of females mature was estimated as 600-650 mm LD, and as 401-500 mm LD, for males. The largest male presented 635 mm DW and the largest female, 1130 mm DW. Dasyatis guttata females have only the left side of the reproductive system functional and the vitellogenesis occurs concomitantly with pregnancy. The average fertility is two uterine embryos and the estimated size at birth is 130 mm DW. The results suggest that individuals reproduce all year, with two reproduction peaks and a gestation of four months. These data should be considered in management plans and conservation of D. guttata.