Quantitative Sex Identification of Hatchling Green Sea Turtles (<i>Chelonia mydas</i>)

Ikonomopoulou, Maria P.; Aland, R. C.; Ibrahim, Kamarrudin; Gosden, Edward; Whittier, Joan M.

doi:10.1670/10-333

Cited by 5 publications

(2 citation statements)

References 20 publications

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“…Kidneys were then prepared as paraffin‐embedded sections and stained with haematoxylin and eosin for light microscopy. Individuals were classified as either male or female or unknown based on the criteria Ceriani and Wyneken (2008) and Ikonomopoulou, Aland, Ibrahim, Gosden, and Whittier (2012), where males are characterized by the presence of seminiferous tubules within the medulla and a regressed cortex, and females are characterized by relatively disorganized medulla and a thick, well‐developed cortex. The identification process was repeated three times for each sample without reference to previous assessment to ensure confidence in sex‐allocation.…”

Section: Methodsmentioning

confidence: 99%

Variation in thermal traits describing sex determination and development in Western Australian sea turtle populations

Bentley

Stubbs

Whiting³

et al. 2020

Functional Ecology

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Both the development rate and sex of sea turtle embryos depend on incubation temperature, as all species of sea turtle are ectotherms and show temperature‐dependent sex determination (TSD). Theory predicts that selection should act on populations to optimize developmental times and primary sex ratios. In this study, we use a consistent methodology to measure development rates and model the reaction norm that defines TSD in three populations of flatback turtles Natator depressus and two populations of green turtles Chelonia mydas that nest in Western Australia. We show that development rates vary between and within species, likely reflecting adaptation to local beach microclimates. Similarly, the parameters that define the TSD reaction norm vary between the two species, and among N. depressus populations, with pivotal temperatures (TPIV) varying by 1.5°C (29.6–31.1°C), and the transitional ranges of temperatures (TRT) varying by 1.4–3.3°C. In contrast, we found a similar TPIV for the two C. mydas populations, but a wider TRT at the northernmost tropical rookery. Our findings support the view that thermal parameters in geographically separated populations of sea turtles are broadly similar, but the variation we describe will be highly relevant for predicting how populations will respond to climate change. A free Plain Language Summary can be found within the Supporting Information of this article.

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Section: Methodsmentioning

confidence: 99%

Variation in thermal traits describing sex determination and development in Western Australian sea turtle populations

Bentley

Stubbs

Whiting³

et al. 2020

Functional Ecology

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“…Therefore, researchers have been employing different techniques to assess the sex of hatchlings. For example, gonadal histology (Merchant-Larios et al, 1989;Godfrey & Mrosovsky, 2006), radioimmunoassay to measure testosterone levels in blood or chorioallantoic fluid (Gross et al, 1995), laparoscopy on live post-hatchlings (Wyneken et al, 2007), direct observations of the gonads in situ (McCoy et al 1983), and clearing of gonads in toto (van der Heiden et al, 1985), quantitative sex identification based on the histological characteristics of the gonads and paramesonephric ducts (Ikonomopoulou et al, 2012) have been used to determine the sex. Some of these techniques require the sacrificing of animals and a complicated long laboratory processes.…”

Section: Introductionmentioning

confidence: 99%

Sex Determination in Green Turtle Hatchlings: Geometric Morphometry and Molecular Sex Markers

Sönmez¹,

Bağda²,

Candan³

et al. 2019

Natural and Engineering Sciences

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Determination of the sex ratio in sea turtle population is one of the most important parameters for the conservation and management of the species. We aimed to the test usability of the more than one approaches that identify the sex of hatchlings with alternative non-invasive methods. Geometric morphometry and molecular sex marker were used to indicate difference between the sexes in the green sea turtle (Chelonia mydas) hatchlings which sexes were previously determined by gonad histology. A total of 60 landmarks were identified from three body parts (carapace, plastron and tail) for geometric morphometry. No sex specific difference was found in these three body parts. Furthermore, we analyzed a total of 55 different oligonucleotide combinations using sex-based pool strategy but found no difference. These two techniques are insufficient for sex determination in the green turtle hatchlings. A relatively small number of the primer combinations and male hatchlings used to identify sex of C. mydas appears to be a disadvantage. In order to obtain clearer results with geometric morphometric and molecular sex markers, it is recommended to compare sexes in laboratory conditions with constant temperature.

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The Influence of Temperature on Embryonic Respiration, Growth, and Sex Determination in a Western Australian Population of Green Turtles (Chelonia mydas)

Stubbs

Mitchell

2018

Physiological and Biochemical Zoology

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Quantitative Sex Identification of Hatchling Green Sea Turtles (Chelonia mydas)

Cited by 5 publications

References 20 publications

Variation in thermal traits describing sex determination and development in Western Australian sea turtle populations

Variation in thermal traits describing sex determination and development in Western Australian sea turtle populations

Sex Determination in Green Turtle Hatchlings: Geometric Morphometry and Molecular Sex Markers

The Influence of Temperature on Embryonic Respiration, Growth, and Sex Determination in a Western Australian Population of Green Turtles (Chelonia mydas)

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