“…Gasterosteus acufeutus L. (Baggerman, 1972(Baggerman, , 1985, Fundulus heteroclitus L. (Day & Taylor, 1984) or Oryzias latipes Schlegel (Chan, 1976), through night interruption experiments. In Heteropneustes fossifis (Bloch), Vasal & Sundararaj (1975) were able to determine the duration of the photo-inducible phase. More recently, Duston & Bromage (1 986) used a resonance procedure to demonstrate the circadian aspect of such a rhythm in Oncorhynchus mykiss (Walbaum).…”