RESPIRATORY GAS-EXCHANGE OF SEA TURTLE NESTS (CHELONIA-CARETTA)
RESPIRATORY GAS-EXCHANGE OF SEA TURTLE NESTS (CHELONIA-CARETTA)
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DOI：
10.1016/0034-5687(77)90062-7
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发表时间：
1977-01-01
期刊：
影响因子：
--
通讯作者：
ACKERMAN, RA
中科院分区：
文献类型：
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作者：
ACKERMAN, RA
海龟在筑巢海滩中精心挖掘的约 50 厘米深的直径 25 厘米的小室中产下约 100 个革壳蛋，这些蛋在 60 天的孵化期内交换气体（温度约为 28 摄氏度）。球形巢室周围的沙子限制了气体进出巢的扩散，因此随着胚胎发育的进展，巢内气体中的 PO2 [O2 分压] 降低，PCO2 增加。在 100 个蛋的人造海龟和卡雷塔巢穴内，PO2 降至 80-100 托，PCO2 升至 40-60 托。发育过程中巢穴中气体张力的变化与鸡蛋气室中看到的非常相似。海龟巢内和巢周围沙子中的气体张力可以通过径向稳态扩散模型来描述。沙子中气体的扩散速率是巢中扩散速率的 30-50%，是等体积空气中扩散速率的 6-12%。海龟巢周围的沙子似乎决定了巢中蛋的气体交换，其功能类似于鸡胚胎周围的壳。雌性海龟可以建造她的巢以最大化其气体交换并最小化巢内的气体分压梯度。
Sea turtles lay about 100 leathery-shelled eggs in a 25 cm diameter chamber carefully excavated about 50 cm deep in a nesting beach, where the eggs exchange gases (at .apprx. 28.degree. C) during their 60 day incubation period. The sand surrounding the spherical nest chamber restricts the diffusion of gases into and out of the nest so that as embryonic development progresses, PO2 [partial pressure of O2] decreases and PCO2 increases in the gas inside the nest. PO2 falls to 80-100 torr and PCO2 rises to 40-60 torr inside 100-egg manmade Chelonia and Caretta nests. The change in gas tensions in the nest during development is very similar to that seen in the air cell of the chicken egg. Gas tensions inside the turtle nest and in the sand surrounding the nest can be described by a radial steady-state diffusion model. The rate of diffusion of gases in the sand is 30-50% of the rate found in the nest and 6-12% of the rate found in an equal volume of air. The sand surrounding the turtle nest appears to determine the gas exchange of the eggs in the nest and is functionally analogous to the shell surrounding the chicken embryo. The female sea turtle may construct her nest so as to maximize its gas exchange and minimize gas partial pressure gradients inside the nest.