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Environmental influences on melatonin secretion in Atlantic cod (Gadus morhua) and their relevance to commercial culture

Citation

Porter, MJR and Stefansson, SO and Nyhammer, G and Karlson, O and Norberg, B and Bromage, NR, Environmental influences on melatonin secretion in Atlantic cod (Gadus morhua) and their relevance to commercial culture, Fish Physiology and Biochemistry, 23, (3) pp. 191-200. ISSN 0920-1742 (2000) [Refereed Article]

DOI: doi:10.1023/A:1007816426509

Abstract

This study investigated the effects of photoperiod and temperature on plasma melatonin secretion in Atlantic cod (Gadus morhua L.). Initial work confirmed the presence of a diel profile of melatonin synthesis, with elevated levels during the dark phase. Unusually for fish, the peak in plasma melatonin occurred towards the end of the dark phase, which is indicative of a type 'A' melatonin profile. When exposed to 60 hours of continuous darkness a clear endogenous rhythm of melatonin synthesis was observed, which continued for 4 cycles with a periodicity which, approximated to 24 h. When acclimated to varying temperatures (4, 8, 12 or 16 °C) no variation in melatonin production was seen, however, body size appeared to be an important influence, with the smallest fish exhibiting significantly higher levels of dark phase melatonin. Finally, the application of additional night-time illumination to cod maintained in sea cages i.e. without blackout, did not significantly reduce dark phase plasma melatonin, suggesting that cod are less sensitive to photoperiod manipulation in cages than salmonids.

Item Details

Item Type:Refereed Article
Research Division:Agricultural and Veterinary Sciences
Research Group:Fisheries Sciences
Research Field:Aquaculture
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - Aquaculture
Objective Field:Fisheries - Aquaculture not elsewhere classified
Author:Porter, MJR (Dr Mark Porter)
ID Code:33952
Year Published:2000
Web of Science® Times Cited:23
Deposited By:TAFI - Aquaculture
Deposited On:2005-07-22
Last Modified:2011-10-04
Downloads:0

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