Como tratar o seu peixe: efeito do procedimento experimental em medidas de comportamento em cativeiro, um estudo com Crenuchus spilurus

Abstract

All behavioral experiments with captive fish involve methods of manipulation and environmental enrichment. Researchers use different methods in order to obtain more reliable, or because using an alternative and more complex method does not would lead to a great change in the results obtained. However, about the effect of using such methods on behavioral characteristics of fish are rare. We present here an evaluation of the effect of using four methods commonly employed in studies on two behavioral variables. Individuals of Crenuchus spilurus have been transferred from their aquariums stock to the aquariums in four different ways, here called "method common "," non-exposure to air "," successive exposure "and" dither fish ". We we have measured the effect of these different forms of manipulation on the of the fish in the experimental aquarium and the time in which they kept away from a comfort zone (a measure of boldness). Our results indicate that the method employed influences the responses to behavioral variables. Simple transfer using aquarium networks (here called the "common method") may be appropriate in studies where the researcher intends to evaluate the exploratory behavior and displacement in the aquarium. Using an apparatus for the transfer of fish (treatment "not exposure to air ") may be indicated for studies in which a movement is unwanted. While widely used for this purpose, exposure of individuals to the experimental environment on consecutive days (here of "successive exposure" method) was not indicated to evaluate time associated with a stimulus and exploitation and repeated manipulation provoked deaths of individuals. Enrich the experimental aquarium with smaller fish ("Dither fish") was effective in reducing shyness and in stimulating behavior of fish. We conclude that the implementation of a given method should be evaluated before repeated use in behavioral experiments.