Neural basis giving rise to speciation in teleost

Reproductive isolation is the elementary process to cause the speciation. However, its forming mechanism is unclear. To elucidate the neural basis of reproductive isolation, we applied the freshwater goby. We detected the expression pattern of c-fos in the brain of male goby, and identified the brain region activated during the courtship behavior for conspecific female or the exclusive behavior against xenogeneic female. Then the difference of neural activity between courtship and exclusive behavior was observed in the neural circuit relating to the visual process, and the pituitary and hypothalamus regulating the systemic reaction. Taken together, it is suggested that the male goby discriminates females depending on the visual perception, and the tectum, the primary input area of vision, is the decision center of behavioral selection.