Accumulation of trace metals in the embryos and hatchlings of Chelonia mydas from Peninsular Malaysia incubated at different temperatures

One of the decisions made by hatchery managers around the world is what degree of shading and nest depth are required to maximise the production of high-quality hatchlings at optimal sex ratios. The primary objectives of this study were to determine the effects of (1) hatchery shading and nest depth on nest temperatures and emergence lag, and (2) nest temperatures and nest depth on hatchling sex ratio and quality. In 2001, 26 Chelonia mydas clutches from Ma’Daerah beach, Terengganu, Malaysia, were relocated alternatively at depths of 50 cm and 75 cm into a 70%-shaded and a 100%-shaded hatchery. Data loggers were placed into the centre of each relocated clutch to record the temperature every hour over the course of incubation. When the hatchlings emerged, a sample of the clutch was run, measured and weighed and a separate sample was examined histologically for sex characteristics. Nest temperatures ranged between 28°C and 30°C and generally showed increases over the second half of incubation due to metabolic heating of the clutch. There was no significant correlation found between nest temperature and any of the hatchling parameters measured. Hatchlings from 75-cm-deep nests had a longer emergence lag (46.4 (±10.2) h) than hatchlings from 50-cm-deep nests. Hatch and emergence success were similar to those of natural populations and hatchling sex ratios were male dominant, with an average of 72% males. There was a poor correlation between mean middle-third incubation temperatures and sex ratio. Hatchlings from 75-cm-deep nests had similar running speeds but lower condition index than their conspecifics from 50-cm-deep nests.

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Trace metals in green sea turtles (Chelonia mydas) inhabiting two southern California coastal estuaries

Chemosphere ◽

10.1016/j.chemosphere.2019.01.107 ◽

2019 ◽

Vol 223 ◽

pp. 342-350 ◽

Cited By ~ 6

Author(s):

Arthur D. Barraza ◽

Lisa M. Komoroske ◽

Camryn Allen ◽

Tomoharu Eguchi ◽

Rich Gossett ◽

...

Keyword(s):

Trace Metals ◽

Southern California ◽

Sea Turtles ◽

Chelonia Mydas ◽

Green Sea Turtles

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Blood Gasses Contents of Green Turtle (Chelonia mydas) Hatch Treated by Different Temperatures

HAYATI Journal of Biosciences ◽

10.4308/hjb.18.3.147 ◽

2011 ◽

Vol 18 (3) ◽

pp. 147-150 ◽

Cited By ~ 3

Author(s):

RINI PUSPITANINGRUM ◽

SEPTELIA INAWATI WANANDI ◽

RONDANG ROEMIATI SOEGIANTO ◽

MOHAMAD SADIKIN

Keyword(s):

Green Turtle ◽

Chelonia Mydas ◽

Different Temperatures

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

Advances in Zoology ◽

10.1155/2014/503209 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 5

Author(s):

Maria P. Ikonomopoulou ◽

Adrian J. Bradley ◽

Kammarudin Ibrahim ◽

Colin J. Limpus ◽

Manuel A. Fernandez-Rojo ◽

...

Keyword(s):

Life Histories ◽

Pearson Correlation ◽

Chelonia Mydas ◽

Plasma Corticosterone ◽

Peninsular Malaysia ◽

Plasma Metabolites ◽

Turtle Species ◽

History Analysis ◽

Nesting Behaviour ◽

High Concentrations

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.

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