Measuring Agonistic Behavior in Zebrafish

Adult zebrafish (Danio rerio ) are territorial, show aggressive behavior, and establish dominant-subordinate hierarchies. Here, a protocol for a standard opponent setup is described, which enables the identification, characterization, and quantification of agonistic activities of zebrafish. Following a period of social isolation, zebrafish are placed into an observation tank, engage in an agonistic encounter, and establish a dominance hierarchy within 15 min. The analysis of the behavior includes quantification of activities such as lateral display, frontal display, chasing and nipping over the course of the observational period with the help of The Observer^� program. As a result, an event plot and a histogram are generated, which show the dynamics of agonistic activities. The described method can be used to quantify the effects of drug treatment or to identify modified activity patterns in mutant zebrafish.