Diet of the lesser electric ray in southern Brazil
Published online in June 2012
Diet of the lesser electric ray Narcine brasiliensis (Olfers, 1831) (Elasmobranchii, Narcinidae) in southern Brazil
Ferreira, L. C. & Vooren, C. M
ABSTRACT:
The objective of this study was to describe the diet of the lesser electric ray (Narcine brasiliensis) in the waters along the coast of Rio Grande do Sul during summer. In February 2005, all individuals caught in bottom trawl fishing hauls of the inshore waters between latitudes 29° S and 34° S were collected. Sex and total length were recorded for each individual; stomachs were fixed in 4% formalin. Food items were identified, and the frequency of occurrence, number and weight proportions, and index of relative importance were calculated for each item. Ingested food was found in 95% of the stomachs of the collected individuals. Polychaetes constituted 97% of total prey, with Notomastus lobatus being the most important food item. Stomach repletion was non-different between the sexes; no correlation was found between the richness of the diet and the total body length and between wet weight of stomach content and total weight. Thus, N. brasiliensis caught in the waters off the coast of southern Brazil during summer feed mostly on polychaetes, which could be the result of the aggregation of rays in areas with the highest abundance of a specific prey because of prey population increase.
Pan-American Journal of Aquatic Sciences (2012), 7(1):37-44