Reproductive biology of Urotrygon microphthalmum (Batoidea: Urotrygonidae) from north-eastern Brazil, tropical west Atlantic Ocean

摘要

The reproductive biology of Urotrygon microphthalmum was studied based on specimens caught as by-catch in shrimp (Litopenaeus schmitti, Xiphopenaeus kroyeri, Farfantepenaeus subtilis and Farfantepenaeus brasiliensis) fishing operations between March 2010 and March 2012 on the coast of Pernambuco, Brazil. Females reached a larger total length (L-T) and total body mass (M-T) (298mm and 148 g) than males (250mm and 90 g). Length at maturity was estimated to be 188 and 199mm L-T for males and females. Uterine fecundity ranged from one to four embryos (mean +/- S.D.: 1.85 +/- 0.45). Size at birth was estimated to be 105mm L-T. Gestation lasted between 4 and 5months. The reproductive cycle of U. microphthalmum is hypothesized to be asynchronous and biannual. (C) 2016 The Fisheries Society of the British Isles