[1].[J].Asian Herpetological Research,2014,5(4):276-280.[doi:10.3724/SP.J.1245.2014.00276]
 Zheng WANG,Longhui LIN and Xiang JI*.Unhatched and Hatched Eggshells of the Chinese Cobra Naja atra[J].Asian Herpetological Research(AHR),2014,5(4):276-280.[doi:10.3724/SP.J.1245.2014.00276]


Asian Herpetological Research[ISSN:2095-0357/CN:51-1735/Q]

Original Article


Unhatched and Hatched Eggshells of the Chinese Cobra Naja atra
Zheng WANG12 Longhui LIN3 and Xiang JI2*
1 College of Biological and Environmental Sciences, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
2 Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, Jiangsu, China
3 Hangzhou Key Laboratory for Animal Adaptation and Evolution, School of Life Sciences, Hangzhou Normal University, Hangzhou 310036, Zhejiang, China
Elapidae Naja atra eggshell structure egg incubation X-ray diffraction spectra minerals
Changes in structure and composition of the eggshell resulting from embryonic mobilization of minerals from the eggshell are found in all oviparous reptiles studied thus far. In this study, we measured samples of unhatched and hatched eggshells of the Chinese cobra Naja atra to determine the percentage of ash and the phase composition of calcium carbonate. The mean percentage of ash was significantly higher in unhatched eggshells (24.6%) than in hatched eggshells (22.3%). The dominant phase in unhatched eggshells was the calcite form of calcium carbonate. In addition to the peaks of calcite, a few small peaks were found to be caused by the aragonite and vaterite phases of calcium carbonate, implying that there are small amounts of aragonite and vaterite in the eggshell. The concentration of the various phases calculated from the intensity of the X-ray diffraction spectra allowed the estimation that percentages of calcite, aragonite and vaterite were about 92%, 4% and 4%, respectively. Hatched eggshells produced similar spectral characteristics as unhatched eggshells, with one exception. The dominant phase composition in the hatched eggshell was also calcite, but the amount of the aragonite phase had a marked increase. Our study adds evidence that embryonic mobilization of minerals from the eggshell may result in changes in structure of the eggshell.


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更新日期/Last Update: 2016-01-25