Espectro trófico de la raya eléctrica Narcine bancroftii (Griffith & Smith 1834) (Elasmobranchii, Narcinidae) en playa Salguero, Santa Marta, Caribe Colombiano
Trophic spectrum of the electric ray Narcine bancroftii (Griffith & Smith 1834) (Elasmobranchii, Narcinidae) in playa Salguero, Santa Marta, Colombian Caribbean. The Bancroft’s numbfish Narcine bancroftii, a common species in coastal fisheries as bycatch, has been scarcely studied. The poor knowledge about important biological aspects and life history do not permit to take control management measures to allow species conservation. We included one important aspect about the diet composition, which include the analysis of 198 stomachs to about the trophic spectrum. Number or prey organism (N), weigh (P), frequency of occurrence (FO), index of relative importance (IRI), diversity, prey uniformity, trophic niche amplitude (Bi), and diet overlapping (Cλ) methods were used. The most important preys were: Sipunculidae, Callianassidae and Ophichthidae. The females shown higher prey diversity values and males had the highest uniformity values. The diet changed ontogenetically and feeding areas were common to both sexes and all stages of development. The Bancroft’s numbfish is considered a specialist ray, eating mainly sipunculids, with a diverse diet including several benthic preys.