Development of open-field and social behavior of the paradise fish (Macropodus opercularis L.).

In a series of experiments, we examined the development of some characteristic behavior elements in the paradise fish. It was shown that the behavior in the open field was dependent on the age of the fish. The attraction of fries of paradise fish toward conspecifics undergo some changes between 12 and 25 days of age: Larger groups become more attractive. Social orientation toward individual conspecifics develops by 24 days of age.