| Abstract: | We measured frequency and duration of different courtship activities of male guppies (especially the simoid display) at different temperatures, by means of direct observations, and video-recorder. We observed that the animals undergoing long-term temperature adaptation show nearly an independence of courtship frequency to the influence of temperature within the range of 20° to 30°C. After transfer to higher or lower temperatures, the frequency of the sigmoid behaviour was diminished. Afterwords, temperature compensation took place. The duration of the sigmoid display was temperature dependent. We concluded that certain fin movements during the sigmoid display were directly temperature dependent, and that lowering the temperature acted as a stressor on sexual motivation. After adaptation to the new temperature (which lasted 4–5 days) the fish were able to show a complete cycle of 5.5 dorsal fin movements per sigmoid display in temperatures between 20° and 30° C. |
