Please use this identifier to cite or link to this item:
|Title:||Influences of photoperiod and alternate days of feeding on plasma growth hormone and thyroid hormone levels in juvenile rainbow trout||Authors:||Reddy, P.K.
|Issue Date:||Jul-2003||Citation:||Reddy, P.K., Leatherland, J.F. (2003-07). Influences of photoperiod and alternate days of feeding on plasma growth hormone and thyroid hormone levels in juvenile rainbow trout. Journal of Fish Biology 63 (1) : 197-212. ScholarBank@NUS Repository. https://doi.org/10.1046/j.1095-8649.2003.00144.x||Abstract:||The diurnal patterns of plasma growth hormone (GH), thyroid hormone and cortisol concentrations in rainbow trout Oncorhynchus mykiss held under three photoperiod (L:D) regimes (6:18, 12:12 and 18:6), and fed either daily (DF) or on alternate days (ADF) with 2.0% body mass per day of a commercial trout diet were determined. The ADF groups had reduced total mass gain and specific growth rates compared with DF fish, but photoperiod had no affect on growth for either of the feeding regime groups. In the ADF groups, the mean 24 h plasma thyroxine (T4) and triiodothyronine (T3) concentrations were significantly lower, both on days of feeding and days of fasting, than in DF fish held under all three photoperiod regimes, but for GH, only the 18L:6D DF group was higher than the comparable ADF groups. There were no significant differences in mean 24 h plasma cortisol concentrations of DF and ADF groups. Diurnal patterns of plasma GH, cortisol, T4 and T3 were found in DF fish held under all three photoperiod regimes. Increases in plasma cortisol changes were associated with the onset of the light phase; elevations in plasma GH and T4 concentrations were more closely associated with clock time, regardless of photoperiod; increases in plasma T3 concentrations were strongly associated with time of feeding. In ADF groups, these diurnal changes in plasma GH, T4 and T3 concentrations were suppressed for both the fed and fast days, and plasma cortisol concentrations were suppressed on the fasting day. The observations are discussed in terms of the proposed anabolic, catabolic and growth regulating roles of these hormones in different growth and metabolic modifying situations in teleosts. © 2003 The Fisheries Society of the British Isles.||Source Title:||Journal of Fish Biology||URI:||http://scholarbank.nus.edu.sg/handle/10635/110877||ISSN:||00221112||DOI:||10.1046/j.1095-8649.2003.00144.x|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Oct 11, 2021
WEB OF SCIENCETM
checked on Oct 11, 2021
checked on Oct 14, 2021
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.