Effect of Starvation on the Characteristics of 24–h Rhythm in Surfacing Activity of an Indian Freshwater Catfish, Clarias batrachus

Abstract

The present study was aimed to examine the effect of starvation on the surfacing activity of an Indian freshwater catfish, Clarias batrachus. Live Clarias batrachus of mixed sex were purchased from the local market and kept in stock aquaria under natural daylength. After proper acclimation, animals were randomly selected and divided into two groups. Animals were exposed under natural daylength and kept in specially designed glass aquaria for recording of the surfacing activity. Animals of one group were fed once a day at a fixed time (14:00 h) while the other group had no food at all for a total period of experiment (8 days). Results clearly indicate that the surfacing activity exhibits a significant 24–h rhythm in both fed and starved groups of animals. Further, the acrophases of the activity are located during the dark phase. A statistically significant effect of time on surfacing activity was validated with the help of ANOVA. The night hour mean of the activity was found significantly higher as compared to the day hour mean. Results of ANOVA also revealed a statistically significant effect due to starvation. The activity in the fed group is significantly increased as compared with starved group. Further, statistically significant rhythms with τ = 12 h and 6 h have also been noticed in both fed and starved groups. It may be concluded that starvation does not affect the multifrequency rhythms in air-breathing activity of Clarias batrachus under natural daylength.