Studies on the Effect of Photoperiodism and Temperature on Moulting of a Freshwater Prawn Macrobrachium dayanum

Abstract

The effect of Photoperiodism and temperature on moulting of a freshwater prawn Macrobrachium dayanum was investigated in the laboratory for 91 days. 60 healthy specimens of M. dayanum, were taken with uniform weight. The experimental prawns were divided into three groups viz, control, continuous 24hrs. dark and continuous 24hrs. light condition. Moulting frequency increased with corresponding increase in photoperiod and temperature 24L: 00D (17.50 ˚C) as compared to control (12L: 12D, 16.49 oC). While lowest moulting rate was recorded in (24D: 00L, 13.15 oC). The highest moulting observed in 24hrs. continuous light indicated longer photoperiodism and rise in temperature gave positive effect on the growth of Macrobrachium dayanum, consumed good feed, and grew faster, due to better assimilation efficiency.