Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 32759
Leatherback Turtle (Dermochelys coriacea) after Incubation Eggshell in Andaman Sea, Thailand Study: Microanalysis on Ultrastructure and Elemental Composition

Authors: M. Areekijseree, M. Pumipaiboon, S. Nuamsukon, K. Kittiwattanawong, C. Thongchai, S. Sikiwat, T. Chuen-Im

Abstract:

There are few studies on eggshell of leatherback turtle which is endangered species in Thailand. This study was focusing on the ultrastructure and elemental composition of leatherback turtle eggshells collected from Andaman Sea Shore, Thailand during the nesting season using scanning electron microscope (SEM). Three eggshell layers of leatherback turtle; the outer cuticle layer or calcareous layer, the middle layer or middle multistrata layer and the inner fibrous layer were recognized. The outer calcareous layer was thick and porosity which consisted of loose nodular units of various crystal shapes and sizes. The loose attachment between these units resulted in numerous spaces and openings. The middle layer was compact thick with several multistrata and contained numerous openings connecting to both outer cuticle layer and inner fibrous layer. The inner fibrous layer was compact and thin, and composed of numerous reticular fibers. Energy dispersive X-ray microanalysis detector revealed energy spectrum of X-rays character emitted from all elements on each layer. The percentages of all elements were found in the following order: carbon (C) > oxygen (O) > calcium (Ca) > sulfur (S) > potassium (K) > aluminum (Al) > iodine (I) > silicon (Si) > chlorine (Cl) > sodium (Na) > fluorine (F) > phosphorus (P) > magnesium (Mg). Each layer consisted of high percentage of CaCO3 (approximately 98%) implying that it was essential for turtle embryonic development. A significant difference was found in the percentages of Ca and Mo in the 3layers. Moreover, transition metal, metal and toxic non-metal contaminations were found in leatherback turtle eggshell samples. These were palladium (Pd), molybdenum (Mo), copper (Cu), aluminum (Al), lead (Pb), and bromine (Br). The contamination elements were seen in the outer layers except for Mo. All elements were readily observed and mapped using Smiling program. X-ray images which mapped the location of all elements were showed. Calcium containing in the eggshell appeared in high contents and was widely distributing in clusters of the outer cuticle layer to form CaCO3 structure. Moreover, the accumulation of Na and Cl was observed to form NaCl which was widely distributing in 3 eggshell layers. The results from this study would be valuable on assessing the emergent success in this endangered species.

Keywords: Leatherback turtle (Dermochelys coriacea), SEM (SEI/EDX), turtle eggshell.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1087548

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1936

References:


[1] K.L. Eckert, K.A. Bjorndal, F. Alberto Abreu-Grobois,and M. Donnelly (Eds). ‘Research and Management Techniques for the Conservation of Sea Turtle, IUCN/SSC Marine Turtle Specialist Group Publication no. 4, Consolidated Graphic Communications, Blanchard, Pennsylvania,232 pages, 1999.
[2] T. Chuen-Im, M. Areekijseree, S. Chongthammakun, and S.V. Graham,“Aerobic bacterial infections in captive juvenile green (Cheloniamydas) and hawksbill (Eretmochelysimbricata) sea turtles from Thailand”, Chelonian Conservation and Biology, vol. 9, no 1, pp. 135-142. DOI: 10.2744/CCB-0808.1., 2010.
[3] M. Areekijseree, S. Nuamsukon, T. Chuen-Im, and N. Narkkong, “Microanalysis on ultrastructure and elemental composition of green turtles (Cheloniamydas) eggshells”. Journal of the Microscopy Society of Thailand, vol.24,no 2, pp. 78-82, 2010.
[4] S.Nuamsukon, T. Chuen-Im, S. Rattanayuvakorn, K. Panishkan, N.Narkkong, and M. Areekijseree, “Thai marine turtle eggshell: Morphology, ultrastructure and composition”. Journal of Microscopy Society of Thailand, vol. 23, no 1, pp. 52-56, 2009.
[5] S. N. Al-Bahry, I.Y. Mahmoud, I.S. Al-Amri, T.A. Ba-Omar, K.O. Melgheit, and A.Y. Al-Kindi, “ Ultrastructural features and elemental distribution in eggshell during pre and post hatching periods in the green turtle, Cheloniamydas at Ras Al-Hadd, Oman. Tissue and Cell, vol. 41, pp. 214-221, 2009.
[6] J. D. Winkler, “Testing phylogenetic implications of eggshell characters in side-necked turtles (Testudines: Pleurodira)”. Zoology, vol. 109, pp.127-136, 2006.
[7] J. C. W. Lam, S. Tanab, S.K.F. Chan, M.H.W. Lam, M. Martin, and P.K.S. Lam, “Levels of trace elements in green turtle eggs collected from Hong Kong: Evidence of risks due to selenium and nickel” Environ. Pollut. vol. 144, pp. 790-801, 2006.
[8] S. Nuamsukon, T. Chuen-Im, P. Peng-Pan, S.Rattanayuvakorn, and M. Areekijseree, “Juvenile sea turtles conservation: Analysis of structure, element of eggshell, microbiological, histological investigation”, In the 9th International Congress on Cell Biology, 7-10 October 2008, Seoul, Korea.