Aggres­sive behav­ior can be of two distinct origins: (1) reactive aggres­sion, as a response to threat­en­ing or danger­ous situa­tions and (2) appet­i­tive aggres­sion, that is motivated by intrin­sic factors, for example positive feelings through the exertion of violence.

Even though much is known about the hormonal and neuronal pathways involved in aggres­sive behav­iors, its remains unclear how intrin­sic and extrin­sic factors shape aggres­sive behav­iors and how those factors affect the transi­tion from reactive to appet­i­tive aggres­sion. Fight­ing fish (genus Betta) have been used in behav­ioral studies since the 1980’s and are a perfect model to study aggres­sive behaviors.

Especially males are highly aggres­sive towards conspecifics which is why they are used for combat­ive inter­ac­tions (similar to cockfights) in some countries in South­east Asia. In the course of this project we want to find out why some fight­ing fish are more aggres­sive than others by using behav­ioral and genetic approaches. By doing so we hope to get a better under­stand­ing of aggres­sive behav­ior in general.