Abstract: This paper studied the feeding rhythms of 5-,8-,and 12-day old paradise fish (Macropodus opercularis) larvae under natural illumination, successive illumination, and successive dark-Under natural illumination, all the test larvae performed a typical daytime feeding rhythm, and fed actively during 12:00-16:00.However, under successive illumination and successive dark, the larvae did not show any identifiable feeding rhythm-Under successive illumination, the larvae fed actively all the day, and their feeding amount during 20:00-next 4:00 was significantly greater than that of the larvae under natural illumination-Conversely, the larvae under successive dark had a lower feeding intensity, particularly during 8:00-16:00, compared with the larvae under natural illumination. In conclusion, M. opercularis larvae performed a typical daytime feeding rhythm, and light condition greatly affected their feeding activity during their early life stages.

Key words: Pesticide, Agricultural areas, Biodiversity