Occurrence and morphologic aspects of treme-treme ray Narcine brasiliensis (Elasmobranchii: Narcinidae) on the coast of São Paulo State, Brasil

Abstract

Rays of the species Narcine brasiliensis have small to medium size and they can reach up to 49 centimeters of total length. They exhibit a nocturnal behavior and live buried in the substrate to protect themselves from predators and to have more efficiency in their feeding, which is mainly composed of small crustaceans. They are usually found in certain regions contaning muddy substrates between southeastern Brazil and northern Argentina; however, there are few studies about their life cycle, distribution aspects, and abundance. This study aims to analyze the occurrence and the proportion of catch of these rays as a bycatch species on artisanal and industrial fisheries in the south-center coast of Sao Paulo, Brazil, and determine morphometric patterns of the species to the southeastern region. For this, 46 morphometric measures will be taken and they will be related to total length and disc width. Statistical tests will be used to analyze if there is a significant difference between young and adults, and males and females. It will be obtained capture points from fisheries to determine the areas of higher concentration of this species.(AU)