Effect of time-restricted feeding on 24-h rhythm in phototactic behavior of zebrafish

ABSTRACT

Among all other repertoire of behaviors, phototactic behavior is one of the most vital behaviors. Our knowledge on the impact of time-restricted feeding on phototactic behavior of fish is critically limited. In this study, we examined the effect of time-restricted feeding schedule on 24-h rhythm in phototactic behavior of zebrafish (Danio rerio). We kept fish in the specially designed aquaria consisting of a photic and a non-photic zone under natural day length condition and fed once in a day, either randomly or at 1200 or 1600. We recorded the frequency of fish in the photic zone every day between 1000 and 1800 for six to nine consecutive days. Statistically significant 24-h rhythms in the frequency of fish were validated at the group level, irrespective of the feeding schedule. It is difficult to explain why the fish fed at 1200 only exhibited food anticipatory activity (FAA). The 24-h average decreased and acrophase delayed significantly in this group as compared with the others. The amplitude of the phototactic rhythm dampened under restricted feeding condition as compared with the fish on random feeding. Nonetheless, the present findings underscore the role of time-restricted feeding as a powerful modulator of the 24-h rhythm in phototactic behavior.

KEYWORDS:

• Zebrafish
• feeding schedules
• phototactic behavior
• time-restricted feeding
• food anticipatory activity

Acknowledgments

The author is thankful to the University Grants Commission, New Delhi, for the research grants received through its DRS-SAP (Phase-III) scheme sanctioned to the School of Studies in Life Science, Pandit Ravishankar Shukla University (PRSU), in the thrust area – Chronobiology. The logistic support was received from the Center for Translational Chronobiology at the School of Studies in Life Science, PRSU, Raipur, which is gratefully acknowledged. I am indebted to Dr. Atanu Kumar Pati, Vice Chancellor of Gangadhar Meher University, Sambalpur – 768004, Odisha, India and Dr. Arti Parganiha of School of Studies in Life Science, Pt. Ravishankar Shukla University, Raipur – 492 010, India for reading the draft of this paper and for offering valuable suggestions for improvement. I am grateful to them for providing me all the essential laboratory facilities for this work. I am also thankful to an unknown reviewer for offering constructive suggestions. This work is one of the components of my PhD thesis.

Disclosure statement

No potential conflict of interest was reported by the author.