Trophic and reproductive aspects of some batoids caught at Santa Marta in the Colombian Caribbean Sea

Abstract

This paper presents the reproductive condition and feeding spectrum of four batoid species caught as bycatch by artisanal fishermen in two sectors of the Colombian Caribbean Sea between August 2005 and September 2006. Specimens were evaluated from a total of 570 hauls done off Salguero beach and 149 off Don Jaca, with sampling periods of 12 to 26 days per month. The total and relative abundance of the batoids caught were determined, as were the sexual proportion and representativity of each sexual maturity stage. Specimens sampled were: 176 Narcine bancroftii (127 females, 49 males); 167 Rhinobatos percellens (83 females, 84 males); 237 Urotrygon venezuelae (126 females, 111 males), and 119 Dasyatis guttata (58 females, 61 males). Although specimens from all stages of maturity were caught, the immature (I) and mature (III) stages were dominant. Based on the sexual proportion obtained, no marked spatial-temporal segregation was observed. The overall diet consisted of crustaceans, annelids, and teleosts, with unique food preferences that allow the sampled species to avoid interspecific competition.