Diet of an endangered Neotropical catfish (<i>Kalyptodoras bahiensis</i>) from the Paraguaçu River, Bahia, Brazil
Alexandre Clístenes de Alcântara Santos, Fabiane Barreto Souza, Edjane Pereira Santos
Abstract
The present study investigates the diet composition and the feeding strategy of Kalyptodoras bahiensis by verifying variations during the hydrological cycle and between males and females. Samples were collected during the periods of rain and drought using various fishing gears adapted to each microhabitat. In laboratory, the fishes were weighed and measured. An abdominal incision was made to observe the gonads for sex determination and the stomach was removed for identification and quantification of food items. The importance of each item in the diet was calculated using the Feeding Index. Amundsen graphic analysis was used to define the feeding strategy. Kalyptodoras bahiensis was classified as an omnivorous species with an invertivorous tendency. The species presented a generalist feeding strategy and many individuals fed on Melanoides tuberculatus, an exotic mollusk that has spread to Brazilian rivers, causing damages to the native community. The high amount and frequency of M. tuberculatus in the diet of K. bahiensis suggest that the species may have a predatory impact on the local population of this mollusk. However, further studies are needed to better understand the interaction between K. bahiensis and M. tuberculatus.