Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/1170
Appears in Collections:Aquaculture Journal Articles
Peer Review Status: Refereed
Title: Clock-Controlled Endogenous Melatonin Rhythms in Nile Tilapia (Oreochromis niloticus niloticus) and African Catfish (Clarias gariepinus)
Author(s): Martinez-Chavez, Carlos Christian
Al‐Khamees, Sammi
Campos-Mendoza, Antonio
Penman, David
Migaud, Herve
Contact Email: hm7@stir.ac.uk
Keywords: Melatonin
Oscillator
Pineal
Tilapia
Catfish
Nile tilapia
Catfishes
Circadian rhythms
Photoperiodism
Issue Date: Jan-2008
Date Deposited: 12-May-2009
Citation: Martinez-Chavez CC, Al‐Khamees S, Campos-Mendoza A, Penman D & Migaud H (2008) Clock-Controlled Endogenous Melatonin Rhythms in Nile Tilapia (Oreochromis niloticus niloticus) and African Catfish (Clarias gariepinus). Chronobiology International, 25 (1), pp. 31-49. https://doi.org/10.1080/07420520801917547
Abstract: The purpose of this work was to investigate the circadian melatonin system in two tropical teleost species characterized by different behavioral habits, Nile tilapia (diurnal) and African catfish (nocturnal). To do so, fish were subjected to either a control photoperiod (12L:12D), continuous light (LL) or darkness (DD), or a 6L:6D photoperiod. Under 12L:12D, plasma melatonin levels were typically low during the photophase and high during the scotophase in both species. Interestingly, in both species, melatonin levels significantly decreased prior to the onset of light, which in catfish reached similar basal levels to those during the day, demonstrating that melatonin production can anticipate photic changes probably through circadian clocks. Further evidence for the existence of such pacemaker activity was obtained when fish were exposed to DD, as a strong circadian melatonin rhythm was maintained. Such an endogenous rhythm was sustained for at least 18 days in Nile tilapia. A similar rhythm was shown in catfish, although DD was only tested for four days. Under LL, the results confirmed the inhibitory effect of light on melatonin synthesis already reported in other species. Finally, when acclimatized to a short photo-cycle (6L:6D), no endogenous melatonin rhythm was observed in tilapia under DD, with melatonin levels remaining high. This could suggest that the circadian clocks cannot entrain to such a short photocycle. Additional research is clearly needed to further characterize the circadian axis in teleost species, identify and localize the circadian clocks, and better understand the environmental entrainment of fish physiology.
DOI Link: 10.1080/07420520801917547
Rights: Published in Chronobiology International. Copyright: Taylor & Francis (Informa Healthcare).; This is an electronic version of an article published in Chronobiology International, Volume 25, Issue 1, January 2008, pp. 31 - 49. Chronobiology International is available online at: http://www.informaworld.com/openurl?genre=article&issn=0742-0528&volume=25&issue=1&spage=31

Files in This Item:
File Description SizeFormat 
STORRE last draft Endogenous melatonin.pdfFulltext - Accepted Version113.85 kBAdobe PDFView/Open



This item is protected by original copyright



Items in the Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

The metadata of the records in the Repository are available under the CC0 public domain dedication: No Rights Reserved https://creativecommons.org/publicdomain/zero/1.0/

If you believe that any material held in STORRE infringes copyright, please contact library@stir.ac.uk providing details and we will remove the Work from public display in STORRE and investigate your claim.