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

Abstract

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 (LT ) and total body mass (MT ) (298 mm and 148 g) than males (250 mm and 90 g). Length at maturity was estimated to be 188 and 199 mm LT 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 105 mm LT . Gestation lasted between 4 and 5 months. The reproductive cycle of U. microphthalmum is hypothesized to be asynchronous and biannual.