The Herpetological Journal

pp.7-12

Authors: Xiang Ji, Ping-yue Sun, Shui-yu Fu & Hua-song Zhang

Abstract: This paper reports data on the mobilization of some yolk and eggshell nutrients and their incorporation into hatchlings and post-hatching yolk in an oviparous colubrid snake, Elaphe carinata. The incubation time at 3 0±0.3°C averaged 50.5 days. During incubation, pliableshelled E. carinata eggs increased in wet mass. Dried shells from freshly laid eggs averaged 8.1 % of the entire egg dry mass. Freshly laid eggs had significantly heavier shells than did hatched eggs with the same wet mass at oviposition. Dry mass conversion from egg contents of the freshly laid egg to hatch ling averaged 81.1 %. During incubation, approximately 63. 7% of non-polar lipids and 72.1 % of energy in egg contents of the freshly laid egg were transferred to the hatchling, with 36.3% of non-polar lipids and 27.9% of energy used for embryogenesis. Shells from freshly laid eggs had a higher level of calcium but a lower level of magnesium than did shells from hatched eggs. Fully developed embryos could obtain all magnesium from yolk but withdrew approximately 30.5% of their total calcium requirements from sources other than yolk. A few days after hatching, a decrease in post-hatching yolk dry mass was accompanied by an increase in carcass dry mass. This confirms that post-hatching yolk could be used to support early growth of hatchlings.