Abstract
The diurnal rhythms of plasma glucose, cortisol, growth hormone (GH) and thyroid hormone (T4, T3) concentrations and hepatic glycogen content were measured in rainbow trout that had been entrained to a specific time of daily feeding (post-dawn, midday, pre-dusk); the purpose of the study was to investigate the significance of feeding time on hormones and metabolite patterns. Plasma GH, cortisol and T4 concentrations all showed evidence of a diurnal rhythm in some treatment groups. There was a significant interaction between the time of feeding and plasma GH and cortisol concentration rhythms; for GH, this appeared to be related to the phase-shifting of the post-prandial increases in plasma GH concentrations, and for cortisol, the rhythms were only evident in fish fed in the post-dawn period [diurnal rhythms were not evident in treatment groups fed in at midday or pre-dusk]. Peak plasma T4 concentrations were evident during the photophase in all three treatment groups; however, the time of feeding had a negligible effect on the timing of those peaks. There were no apparent diurnal rhythms of plasma T3 and glucose concentrations, hepatic glycogen content or hepatosomatic index in any of the three treatment groups.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References cited
Baker, B.I. and Rance, T.A. 1980. Circadian changes in plasma cortisol concentrations in the trout. Gen. Comp. Endocrinol. 40: 344 (abstract).
Bry, C. 1982. Daily variations in plasma cortisol levels of individual female of rainbow trout, Salmo gairdneri: evidence for a post-feeding peak in well-adapted fish. Gen. Comp. Endocrinol. 48: 462–468.
Boujard, T., Brett, S., Lin, L. and Leatherland, J.F. 1993. Effect of restricted access to demand-feeders on diurnal pattern of liver composition, plasma metabolites and hormone levels in Oncorhynchus mykiss. Fish Physiol. Biochem. 11: 337–344.
Boujard, T. and Leatherland, T.J. 1992a. Circadian rhythms and feeding time in fishes. Env. Biol. Fishes 35: 111–122.
Boujard, T. and Leatherland, T.J. 1992b. Demand-feeding behaviour and diel cycle of feeding activity in Oncorhynchus mykiss held under different photoperiod regimes. J. Fish. Biol. 40: 535–544.
Boujard, T. and Leatherland, T.J. 1992c. Diel pattern of hepatosomatic index, liver glycogen and lipid content, plasma non-esterified free fatty acid, glucose, T3, T4, growth hormone and cortisol concentrations in Oncorhynchus mykiss held in different photoperiod regimes and fed using demand feeders. Fish Physiol. Biochem. 10: 111–122.
Cook, R.F. and Eales, J.G. 1987. Effects of feeding and photocycle on diel changes in plasma thyroid hormone levels in rainbow trout, Salmo gairdneri. J. Exp. Zool. 242: 161–169.
Delahunty, G., Olcese, J., Prack, M., Vodicnik, M.J., Schreck, C.B. and De Vlaming, V. 1978. Diurnal variations in the physiology of the goldfish Carassius auratus. J. Interdisc. Cycle Res. 9: 73–88.
Eales, J.G., Hughes, M. and Uin, L. 1981. Effect of food intake on diel variations in plasma thyroid hormone levels in rainbow trout, Salmo gairdneri. Gen. Comp. Endocrinol. 45: 167–174.
Farbridge, K.J. and Leatherland, J.F. 1991. The development of a noncompetitive enzyme-linked immunosorbent assay for oncorhynchid growth hormone using monoclonal antibodies. Gen. Comp. Endocrinol. 82: 7–17.
Garcia, L.E. and Meier, A.H. 1973. Daily rhythms in concentration of plasma cortisol in male and female gulf killifish, Fundulus grandis. Biol. Bull. 144: 471–479.
Gutierrez, J. Carrilo, M., Zanuy, S. and Planas, J. 1984. Daily rhythms of insulin and glucose levels in the plasma of sea bass, Dicentrarchus labrax after experimental feeding. Gen. Comp. Endocrinol. 55: 393–397.
Laidley, C.W. and Leatherland, J.F. 1988. Circadian studies of plasma cortisol, thyroid hormone, protein, glucose and ion concentration, liver glycogen concentration and liver and spleen weight in rainbow trout, Salmo gairdneri Richardson. Comp. Biochem. Physiol. 89A: 495–503.
Leatherland, J.F., McKeown, B.A. and John, T.M. 1974. Circadian rhythm of plasma prolactin, growth hormone, glucose and free fatty acid in juvenile kokanee salmon, Oncorhynchus nerka. Comp. Biochem. Physiol. 47A: 821–828.
Lo, S., Russel, J.C. and Taylor, A.W. 1970. Determination of glycogen in small tissue samples. J. Appl. Physiol. 28: 234–236.
Meier, A.H. 1993. Circadian basis for neuroendocrine regulation. In Rhythms in Fishes. pp. 109–126. Edited by M.A. Ali, Plenum Press, New York.
Perez, J., Zanuy, S. and Carrillo, M. 1988. Effects of diet and feeding time on daily variations in plasma insulin, hepatic cAMP and other metabolites in a teleost, Diecentrarchus labrax L. Fish Physiol. Biochem. 5: 191–197.
Peter, R.E., Hontela, A., Cook, A.F. and Pauleneu, C.R. 1978. Daily cycles in serum cortisol levels in the goldfish: effects of photoperiod, temperature, and sexual condition. Can. J. Zool. 56: 2443–2448.
Pickering, A.D. and Pottinger, T.G. 1983. Seasonal and diel changes in plasma cortisol levels of the brown trout, Salmo trutta L. Gen. Comp. Endocrinol. 49: 232–239.
Rance, T.A., Baker, B.I. and Webley, G. 1982. Variations in plasma cortisol concentrations over a 24-hour period in the rainbow trout, Salmo gairdneri. Gen. Comp. Endocrinol. 48: 269–274.
Spieler, R.E. 1993. Feeding entrained circadian rhythms in fishes. In Rhythms in Fishes. pp. 137–148. Edited by M.A. Ali, Plenum Press, New York.
Spieler, R.E. and Noeske, T.A. 1984. Effects of photoperiod and feeding schedule on diel variations of locomotor activity, cortisol, and thyroxine in goldfish. Trans. Am. Fish. Soc. 113: 528–539.
Author information
Authors and Affiliations
Additional information
To whom correspondence should be addressed
Rights and permissions
About this article
Cite this article
Reddy, P.K., Leatherland, J.F. Does the time of feeding affect the diurnal rhythms of plasma hormone and glucose concentration and hepatic glycogen content of rainbow trout?. Fish Physiol Biochem 13, 133–140 (1994). https://doi.org/10.1007/BF00004338
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00004338