Factors triggering floodplain fish emigration: Importance of fish density and food availability.

Emigration is a widespread phenomenon among fish species in seasonal habitats, but little is known about the factors which trigger this behaviour. In controlled experiments using Tilapia guineensis, a species widely occurring in the seasonal floodplains of West Africa, density of fish played a significant role in triggering fish migration, whereas a lack of food available caused an increase in exploratory behaviour but with no impact on successful emigration. The impact of fish density and subsequently interactions between individuals on emigration suggests that this may be an important causal factor of emigration in fish species exhibiting social interactions.