Table of Contents
Advances in Zoology
Volume 2014 (2014), Article ID 503209, 9 pages
http://dx.doi.org/10.1155/2014/503209
Research Article

Hormone and Metabolite Profiles in Nesting Green and Flatback Turtles: Turtle Species with Different Life Histories

1School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
2Institute for Molecular Bioscience, Level 2 North, The University of Queensland, Services Road, Building 80, St Lucia Campus, St Lucia, QLD 4072, Australia
3Department of Marine Parks Malaysia, No. 25 Persiaran Perdana, Presint 4, 62574 Putrajaya, Malaysia
4Queensland Department of Environment and Heritage Protection, Australia
5Hepatic Fibrosis Group, Queensland Institute of Medical Research, 300 Herston Road, QLD 4006, Australia
6Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, QLD 4059, Australia

Received 16 April 2014; Revised 5 August 2014; Accepted 17 August 2014; Published 27 August 2014

Academic Editor: Raine Kortet

Copyright © 2014 Maria P. Ikonomopoulou et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Herbivorous turtle, Chelonia mydas, inhabiting the south China Sea and breeding in Peninsular Malaysia, and Natator depressus, a carnivorous turtle inhabiting the Great Barrier Reef and breeding at Curtis Island in Queensland, Australia, differ both in diet and life history. Analysis of plasma metabolites levels and six sex steroid hormones during the peak of their nesting season in both species showed hormonal and metabolite variations. When compared with results from other studies progesterone levels were the highest whereas dihydrotestosterone was the plasma steroid hormone present at the lowest concentration in both C. mydas and N. depressus plasma. Interestingly, oestrone was observed at relatively high concentrations in comparison to oestradiol levels recorded in previous studies suggesting that it plays a significant role in nesting turtles. Also, hormonal correlations between the studied species indicate unique physiological interactions during nesting. Pearson correlation analysis showed that in N. depressus the time of oviposition was associated with elevations in both plasma corticosterone and oestrone levels. Therefore, we conclude that corticosterone and oestrone may influence nesting behaviour and physiology in N. depressus. To summarise, these two nesting turtle species can be distinguished based on the hormonal profile of oestrone, progesterone, and testosterone using discriminant analysis.