GASTRIC LAVAGE FOR DIETARY STUDIES OF SMALL FISHES: EFFICIENCY, SURVIVAL AND APPLICABILITY.

Studies on feeding ecology provide information of great importance to the understanding of aquatic ecosystems. However, these studies usually require the sacrifice of animals. In view of this problem, the presently reported study aims to evaluate the effectiveness and applicability of the gastric lavage method for small catfishes. There was no mortality recorded for the 80 specimens of Rhamdia quelen (Quoy et Gaimard, 1824) and after recovery from anaesthesia all fish presented a normal swimming pattern. With the gastric lavage method we were able to retrieve 71.4% of the stomach contents of 34 specimens of Pimelodella pappenheimi Ahl, 1925. These results serve as a stimulus for studies prioritizing non-lethal techniques. These methods would ensure greater knowledge about ecology and conservation of smaller fishes, especially to populations of small and rare species that are the most endangered in freshwater systems. [ABSTRACT FROM AUTHOR]