Quantitative sex identification of hatchling green sea turtles (Chelonia mydas)

Ikonomopoulou, Maria P., Aland, Rachel C., Ibrahim, Kamarrudin, Gosden, Edward and Whittier, Joan M. (2012) Quantitative sex identification of hatchling green sea turtles (Chelonia mydas). Journal of Herpetology, 46 3: 331-337. doi:10.1670/10-333

Author Ikonomopoulou, Maria P.
Aland, Rachel C.
Ibrahim, Kamarrudin
Gosden, Edward
Whittier, Joan M.
Title Quantitative sex identification of hatchling green sea turtles (Chelonia mydas)
Formatted title
Quantitative sex identification of hatchling green sea turtles (Chelonia mydas)
Journal name Journal of Herpetology   Check publisher's open access policy
ISSN 0022-1511
Publication date 2012-09-01
Sub-type Article (original research)
DOI 10.1670/10-333
Open Access Status Not Open Access
Volume 46
Issue 3
Start page 331
End page 337
Total pages 7
Place of publication Salt Lake City, UT, United States
Publisher Society for the Study of Amphibians and Reptiles
Language eng
Abstract Since the 1980s it has been known that incubation temperature influences the sex ratio of sea turtle hatchlings emerging from their nests, and there has been much speculation on how global climate change might threaten sea turtle populations by raising nest temperatures and causing highly female-biased hatchling sex ratios. More recently, studies have indicated that incubation temperature can also influence the size and locomotor performance of sea turtle hatchlings. Here I review recent studies that have explored the influence of incubation temperature on sea turtle hatchling quality in terms of hatchling morphology and locomotor performance. I also discuss the likely underlying mechanisms responsible for incubation temperature-induced differences in hatchling locomotor performance, and how an increase in nest temperature associated with global warming might affect recruitment of sea turtle hatchlings.
Formatted abstract
The histological characteristics of the gonads and paramesonephric ducts were investigated to allow a quantitative distinction among male, female, and intersex hatchling Green Sea Turtles (Chelonia mydas) from peninsular Malaysia. Hatchling sexes were identified initially as either males or females based on the incubation temperatures, and intersex hatchlings were collected from in situ nests. Traditionally, this assignment is confirmed by qualitative visual assessment of histological sections of the gonads and paramesonephric ducts. We describe a quantitative method for measuring these parameters to distinguish hatchling sex. The thickness of the paramesonephric duct epithelium area, the height of the nucleus in cells within the gonadal cortical epithelium, and the width of the gonadal ridge were measured in sections from 116 hatchlings. Upon examination of the histological material, hatchlings identified initially by incubation temperature as females were found to have significantly thicker paramesonephric duct epithelium and greater gonadal ridge width and cortical epithelium nuclear height compared with hatchlings identified as males. In addition, some hatchlings demonstrated histological characteristics of both sexes (designated here as intersex hatchlings) in some or all of the traditional histological sexing criteria. The “intersex” group could be divided into two subgroups by the quantitative measurements described here. Using this method, hatchlings could be classified as either males, females, or intersexes with a male-appearing gonad and female-appearing duct or a female-appearing gonad and male-appearing duct. The method outlined here provides a quantitative way to distinguish sex and provides insight in intersex grouping in hatchling C. mydas.
Keyword locomotor performance
nest temperature
sea turtle hatchling
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2013 Collection
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