Nocturnal activity in the green sea turtle alters daily profiles of melatonin and corticosterone

Jessop, Tim S., Limpus, Colin J. and Whittier, Joan M. (2002) Nocturnal activity in the green sea turtle alters daily profiles of melatonin and corticosterone. Hormones and Behavior, 41 4: 357-365. doi:10.1006/hbeh.2002.1775

Author Jessop, Tim S.
Limpus, Colin J.
Whittier, Joan M.
Title Nocturnal activity in the green sea turtle alters daily profiles of melatonin and corticosterone
Journal name Hormones and Behavior   Check publisher's open access policy
ISSN 0018-506X
Publication date 2002
Sub-type Article (original research)
DOI 10.1006/hbeh.2002.1775
Volume 41
Issue 4
Start page 357
End page 365
Total pages 9
Place of publication New York
Publisher Academic Press
Collection year 2002
Language eng
Subject C1
270502 Neurobiology
780105 Biological sciences
Abstract In nature, green turtles (Chelonia mydas) can exhibit nocturnal activity in addition to their typically diurnal activity cycle. We examined whether nocturnal activity in captive and free-living green turtles altered daily plasma profiles of melatonin (MEL) and corticosterone (CORT). In captivity, diurnally active green turtles expressed distinct diel cycles in MEL and CORT; a nocturnal rise was observed in MEL and a diurnal rise was observed in CORT. However, when induced to perform both low- and high-intensity nocturnal activity, captive green turtles exhibited a significant decrease in MEL, compared to inactive controls. In contrast, plasma CORT increased significantly with nocturnal activity, and further, the relative increase in CORT was correlated with the intensity of the nocturnal behavior. In free-living green turtles that performed nocturnal activity including: nesting, mate searching, and feeding/swimming behaviors, plasma profiles in MEL and CORT exhibited relatively little, or no, daily fluctuation. Our findings demonstrate that nocturnal activity in green turtles is often associated with MEL and CORT profiles that resemble those measured during the day. We speculate that these conspicuous changes in MEL and CORT during nocturnal activity could either support or promote behaviors that enable acquisition of transient resources important to the survival and reproductive success of green turtles. (C) 2002 Elsevier Science (USA).
Keyword Behavioral Sciences
Endocrinology & Metabolism
Daily Hormone Cycles
Daily Resource Availability
Nocturnal Activity
Green Turtle
Chelonia Mydas
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Biomedical Sciences Publications
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Created: Tue, 14 Aug 2007, 17:25:50 EST