Circadian Variation of the RNA/DNA Ratios in Marbled Flounder Pleuronectes yokohamae

Abstract

Laboratory-reared marbled flounder (Pleuronectes yokohamae) juveniles (23.2±0.2mm total length; age 89 day) were sampled over a 48-h period to determine any diel patterns in RNA/DNA ratios. RNA/DNA ratios were highest during daytime periods (0800, 1100, 1400, 1700 h) and significantly reduced at night (2000, 2300, 0200, 0500 h). Findings from this study indicate a diel variation in biochemical condition and suggest that special care should be taken in designing sampling plans, including sampling time and data analysis to account for this source of variability.