Von charmanten Flegeln, besessenen Revierbesitzern und zitternden Partnern – das spannende Verhalten der Hochlandkärplinge

" Splitfins are ethologically highly interesting fish and in the aquarium they serve as exploitable and fascinating objects of study. Generally, they have territorial behavior and the males of many species establish hierarchies. Dominant males demonstrate their rank through special intensity of their coloration and also by their behavior in driving inferior males out of their immediate vicinity or, in the case of territorial species, out of their territory. The larger, stouter females also dominate the inferiors of their own sex.

An exaggerated, i.e. unnatural. level of aggressiveness is mainly due to inappropriate living conditions in the aquaria, which are caused by too small containers, unsuitable group constellations and daily high quality nutrition leading to a lack of activeness in the search for food.

Display and mating are also exciting to witness. Young males already start courting the females when they are not yet mature. Adult goodeids court their partners intensively. In the course of the ongoing courtship. males and females synchronize their motions. In doing so they swim closely side by side and at the climax of mating the male's andropodium is able to seal the genital orifice of the female "