南草蜥胚胎生长及物质和能量动用

用3种水热条件下(3温度×1湿度)孵化南草蜥(Takydomus sexlineatusDaudiin)卵以观测孵化卵质量变化、卵大小、孵化期、胚胎发育及孵出幼体特征。孵化过程中, 每5 d测定卵质量和大小。初生幼体称重后冰冻处死, 解剖分离为躯干、剩余卵黄和腹脂肪体, 65 ℃恒温干燥后称重。不同孵化温度对孵化期的长短有明显影响, 孵化期随孵化温度升高而缩短, 24 ℃平均41.8 d、27 ℃平均35.4 d、30 ℃平均34.0 d。卵孵化到14 d肉眼可见胚胎, 此后胚胎发育变化明显加速。孵化温度显著影响孵出幼体的质量、大小。本实验的受精卵在24 ℃、27 ℃中孵出的幼体质量较大。24 ℃、27 ℃发育的胚胎对卵黄的利用最充分, 剩余卵黄少。     

水热环境对白条草蜥孵化卵和孵出幼体表型特征的影响

用4×2(温度×湿度)八种水热环境孵化安徽滁州琅琊山白条草蜥(Takydromus wolteri)卵,观测孵化卵重量变化、胚胎利用卵内物质和能量以及孵出幼体的特征。卵从孵化环境中吸水导致重量增加,卵重量的增加与入孵卵重量、孵化温度和基质湿度有关。两种孵化基质湿度对孵化期、孵化成功率、孵出幼体性比和大小都无显著影响。孵化期随恒定孵化温度的升高而缩短,27℃、30℃和33℃孵化期分别为32.5、24.9和23.0d,波动温度孵化期为31.1d。33℃孵化成功率最低(42.8%)。温度对孵化成功率和孵出幼体的性别无显著影响,但显著影响胚胎对卵内物质的动用、幼体的大小和重量。33℃不适宜孵化白条草蜥卵,该温度下孵出的幼体躯干小,剩余卵黄多,运动能力差。27℃和波动温度中孵出幼体躯干发育良好,各项被测定的特征指标极其相似。     

水热环境对中国石龙子孵化卵、孵化成功率及孵化幼体特征的影响

用8种水热条件孵化中国石龙子（Eumeces chinensis）卵,观测孵化卵质量变化、胚胎利用卵内物质和能量及孵出坳体特征,孵化卵因净吸水增重,卵增重与入孵卵质量、孵化温度和基质湿度有关。孵出幼体湿重的处理间差异主要是因为幼体水分含量不同。温度显著影响孵化期、孵化卵吸水量、胚胎利用孵内物质和能量几乎所有被检的幼体特征;温度甚至影响胚胎动用卵壳无机物。然而,在24－32℃范围内,温度对卵孵化成功率无显著的影响。32℃孵出幼体比较低于此温度的孵出幼体发育差,表现为躯干小、未利用的卵黄多。此外,32℃孵出幼体的运动表现比低温孵出幼体差,表现为特定体长（snout-vent length,SVL）的疾跑速小于低温孵出幼体,表明高温孵化卵对孵出幼体的运动能力有不利的影响,潮湿基质中旗子同幼体的体长和尾长大于干燥基质中孵出的幼体,并特征性地具有较小的剩余卵黄。24℃胚胎发育能耗较大,胚胎从卵壳动用的无机物较少。温度影响孵出幼体的体形和头部大小,30℃孵出幼体的尾长最大,32℃孵出幼体的头部最小,其质湿度对孵出幼体的体形和头部大小无显著的影响。温度对孵出幼体特征的影响与湿度的影响无关。孵化水热环境诱导的幼体大小、质量和形态差异可能对幼体的生存和适应性具有重要的影响。26－30℃为孵化中国石龙子卵的适宜温度范围。     

孵化温度对灰鼠蛇卵孵化期、孵化成功率和孵出幼体特征的影响

用4个恒定温（24－32℃）孵化灰鼠蛇卵,检测温度对孵化期,孵化成功率和孵出幼体特征的影响。在24－32℃范围内,孵化温度显影响孵化期及孵出幼体的体长和剩余卵黄大小,但不影响孵化成功率和孵出幼体的性别,体重,躯干重和脂肪体重。24,26,30和32℃孵化期分别为99．0,72．2,54．7和48．7d。24℃和26℃孵出幼体的体筮大于30℃和32℃孵出幼体;24℃和32℃孵同幼体内的卵黄较多。不同温度下发育的胚胎对卵内物质和能量的利用一定的差异,但差异不显。雌性幼体的体长,尾长和总长均大于雄性幼体,这些两性差异与孵化温度无关。孵出幼体和新生卵内容的灰分含量无显差异,孵化前后卵壳灰分含量也无显差异,表明灰鼠蛇的卵黄可提供胚胎发育所需的所有无机物。     

孵化温度对白条草蜥孵出幼体大小、形态和运动表现的影响

实验用白条草蜥(Takydrous wolteri）卵由1999年和2000年4月捕自安徽滁州的19条成年雌体产出。用4个恒定温度（24-33℃）孵化白条草蜥卵,检测孵化温度对孵出幼体大小、形态和运动表现的影响。孵化卵从环境中吸不导致生量增加,卵重量增加与卵初始重量和孵化温度有关。24、27、30和33℃孵化期的平均值分别为41.9、30.6、6.25和22.6d。温度显著影响孵化成功率及孵出幼体的湿重、躯干干重和剩余卵黄干重,但对孵出幼体的性别、体长、尾长和干重无显著影响。24℃和27℃孵出幼体湿重和躯干干重大于33℃孵出幼体,剩余卵黄干则小于33℃孵出幼体;30℃和33℃孵出幼体的湿重、躯干干重和剩余卵黄干重无显著差异。孵化温度显著影响孵出幼体一些局部形态特征：24℃和27℃孵出幼体头长和头宽矫正值显著大于高温（33℃）孵出幼体,24℃孵出幼体耳径正值一般小于较高温度孵出的幼体。疾跑速与幼体体长成正相关,与幼体尾长和状态无关。高温孵出幼体运动能力较差。雄笥幼体腹鳞行数少于雌性幼体,尾长和后肢长大于雌性幼体,这些特征的两性差异与孵化温度无关。孵化热环境能诱导白条草蜥部分表型特征的变异,这些特征的变异可能对个体的适应性具有长期的影响。     

孵化温度对黄喉拟水龟胚胎发育和幼体特征的影响

用3个恒定温度(24、26和28℃)孵化黄喉拟水龟南方种群卵,检测孵化温度对孵化期、孵化成功率和孵出幼体特征的影响。孵化温度显著影响孵化期和孵化成功率、以及幼体的性别、大小和早期生长。黄喉拟水龟幼体的性别取决于孵化温度(属TSDⅠa型),26℃和28℃孵出幼体偏雄性,30℃孵出幼体都是雌性。随着孵化温度的升高,孵化期呈非线性缩短,而孵化成功率略微增加。较高温度下孵出的幼体较大且具有较好的功能表现,但生长较慢。低温孵出幼体较小,但胚后生长速率较快。低温孵出幼体较小可能与胚胎发育期长、总代谢消耗大有关;而生长速率快则可能是因为低温产生的雄性幼体生长快于高温产生的雌性幼体。与已报道的黄喉拟水龟北方种群卵孵化结果相比较,26℃和28℃条件下南方种群卵的孵化期和产生1∶1性比的关键温度较大。这种地理上的变异可能反映不同种群对当地热环境适应性上的差异。     

孵化温度对王锦蛇胚胎代谢和幼体适合度的影响

孵化温度所驱动的爬行动物的表型变异是生理生态学研究的热点。本研究以王锦蛇(Elaphe carinata)为实验动物,检验了24℃和28℃孵化温度对王锦蛇胚胎代谢速率、孵化过程中的卵重量、孵出幼体代谢和行为的影响。研究结果显示:卵重和胚胎的呼吸代谢均与孵化时间呈正相关;28℃下胚胎代谢速率大于24℃;幼蛇孵出15 d内体重随着生长时间的延长而减小,24℃孵出幼体的代谢速率大于28℃孵出幼体,两温度下孵出幼体的呼吸代谢速率和生长时间无显著关系;28℃孵出幼体的疾游速和吐信频次均大于24℃;两孵化温度孵出幼体的选择体温无显著差异,但在消耗完体内的剩余卵黄后28℃孵出幼体有60%的个体摄食,而24℃孵出幼体无摄食个体。总体而言,王锦蛇28℃孵出幼体适合度优于24℃孵出幼体。     

孵化温度对乌龟胚胎能量利用及矿物质代谢的影响

在24℃、27℃、30℃和33℃条件下孵化乌龟(Chinemysreevesii)卵,检测温度对胚胎利用卵内能量和矿物质的影响。孵化温度显著影响乌龟胚胎的能量利用。卵在温和温度下(27℃和30℃)比在高温(33℃)和低温(24℃)孵化有较高的干物质、脂肪和能量转化率。因而,27℃和30℃新生幼体的总能量高于33℃和24℃下孵出的幼体。新生幼体内剩余卵黄随温度升高而增大。27℃下新生幼体的躯干能量显著高于其它温度。此外,孵化温度显著影响乌龟胚胎钙代谢,但对镁和钾代谢影响微弱。24℃下胚胎从卵黄和卵壳吸收的总钙量小于其它温度条件下胚胎,与之相对应,24℃下孵出卵卵壳内残留较多的钙。由此可见,温和温度(27-30℃)可提高胚胎能量转化效率,促进胚胎从卵黄和卵壳吸收较多的矿物质,有利于孵出发育良好的乌龟幼体     

安徽宿州山地麻蜥卵孵化温度效应

用3个恒定温度(27、30、33℃)和波动温度(14.0～37.5℃)孵化山地麻蜥(Eremias brenchleyi)卵。结果表明,各温度处理下卵孵化成功率差异不显著,但温度对孵化期、孵出幼体表型特征及疾跑速度有显著影响;27、30℃和波动温度下孵出幼体的SVL、重量及躯干干重比33℃的要大,33℃孵出幼体的运动能力比其他3个温度处理弱。波动温度处理下山地麻蜥卵虽短期经历潜在致死的极端温度,但对孵化成功率、孵出幼体表型特征和运动表现均无负效应。     

荒漠沙蜥胚胎生长发育的温度适应性研究

为研究荒漠沙蜥胚胎发育的温度适应性,我们设定了3个温度(26℃、30℃、34℃)孵化荒漠沙蜥受精卵,并在胚胎孵化过程中对胚胎代谢和心率、新生幼体的形态学特征和幼体静止代谢率的温度适应性进行了研究。结果显示,随着卵的发育,荒漠沙蜥的胚胎代谢率和心率逐渐上升,在孵化后期达到最大;胚胎的心率对孵化温度具有较高的敏感性,随环境温度上升心率显著加快。孵化温度对荒漠沙蜥新生幼体的部分形态学指标有显著影响,26℃下孵化的荒漠沙蜥幼体体型较大。新生幼体的代谢率均比胚胎代谢率高,且不同温度下孵出的幼体其热适应性有较大差异,30℃组孵化出的新生幼体代谢水平最低。我们推测幼体在与孵化温度相同的环境下消耗较少的能量便可保证基本的生理活动需求;相反,个体需要消耗更多的能量才能适应从胚胎到幼体的不同生活史阶段的环境温度变化。     

孵化水热环境对渔异色蛇孵化卵和孵出幼体的影响

渔异色蛇卵孵化时能从环境中吸收水分导致质量增加,卵质量的增加与初始卵质量和孵化基质湿度有关。较大幅度的孵化基质湿度变化对孵化期、孵化成功率、胚胎动用孵内物质和能量、孵出幼体的性比、大小和质量无显著影响。孵化期随温度升高而缩短,并显示极强的窝间差异。温度对孵出幼体的性别无影响,但显著影响孵化成功率、胚胎对卵内物质和能量的动用、幼体的大小和质量、躯干和剩余卵黄的质量。孵出幼体总长的两性差异不显著,但雌体体长大于雄体而尾长小于雄体。３２℃不适于孵化渔异色蛇卵,该温度下孵出的幼体躯干发育不良,剩余孵黄较多,尾部均呈畸形,孵化过程中能量转化率较低。２４℃和２６℃中孵出的幼体躯干发育良好,孵化过程中能量转化率较高,各项被测定的幼体特征指标均极相似。     

恒定和波动温度下丽斑麻蜥孵出幼体的表型变异

作者以丽斑麻蜥(Eremias argus)为模型动物研究恒定和波动孵化温度对孵化成功率和孵出幼体表型的影响。卵在四个恒定[24 ,27 ,30 and 33 (±0·3)℃]、一个波动温度下孵化。不同温度处理下的孵化成功率相同,但孵出幼体表型不同。孵化期随孵化温度升高呈指数式缩短;在相同平均温度下,波动温度孵化卵的孵化期比恒温孵化卵长。在所有被检表型特征中,幼体的干重、剩余卵黄干重和运动表现更易受孵化温度影响。总体而言,低温(24℃、27℃)孵出幼体运动表现最佳,高温(33℃)孵出幼体最差、温和温度(30℃和波动温度)孵出幼体居中。本文研究数据显示: (1)丽斑麻蜥卵每日短期暴露于潜在致死的极端温度下对孵化成功率和孵出幼体形态特征无明显的不利效应; (2)温度波动对孵出幼体运动表现无促进作用,对孵化期的影响则不同于平均值相同的恒定温度。     

Influence of incubation temperature on hatching success,energy expenditure for embryonic development,and size and morphology of hatchlings in the oriental garden lizard,Calotes versicolor (Agamidae)

We incubated eggs of Calotes versicolor at four constant temperatures ranging from 24 degrees C to 33 degrees C to assess the effects of incubation temperature on hatching success, embryonic use of energy, and hatchling phenotypes that are likely to affect fitness. All viable eggs increased in mass throughout incubation due to absorption of water, and mass gain during incubation was dependent on initial egg mass and incubation temperature. The average duration of incubation at 24 degrees C, 27 degrees C, 30 degrees C, and 33 degrees C was 82.1 days, 60.5 days, 51.4 days, and 50.3 days, respectively. Incubation temperature affected hatching success, energy expenditure for embryonic development, and several hatchling traits examined, but it did not affect the sex ratio of hatchlings. Hatching success was lowest (3.4%) at 33 degrees C, but a higher incidence of deformed embryos was recorded from eggs incubated at this temperature compared to eggs incubated at lower temperatures. Most of the deformed embryos died at the last stage of incubation. Energy expenditure for embryonic development was, however, higher in eggs incubated at 33 degrees C than those similarly incubated at lower temperatures. A prolonged exposure of eggs of C. versicolor at 33 degrees C appears to have an adverse and presumably lethal effect on embryonic development. Hatching success at 24 degrees C was also low (43.3%), but hatchlings incubated at 24 degrees C did not differ in any of the examined traits from those incubated at two intermediate temperatures (27 degrees C and 30 degrees C). Hatchlings incubated at 33 degrees C were smaller (snout-vent length, SVL) than those incubated at lower incubation temperatures and had larger mass residuals (from the regression on SVL) as well as shorter head length, hindlimb length, tympanum diameter, and eye diameter relative to SVL. Hatchlings from 33 degrees C had significantly lower scores on the first axis of a principal component analysis representing mainly SVL-free head size (length and width) and fore- and hindlimb lengths, but they had significantly higher scores on the second axis mainly representing SVL-free wet body mass. Variation in the level of fluctuating asymmetry in eye diameter associated with incubation temperatures was quite high, and it was clearly consistent with the prediction that environmental stress associated with the highest incubation temperatures might produce the highest level of asymmetry. Newly emerged hatchlings exhibited sexual dimorphism in head width, with male hatchlings having larger head width than females.     

The effects of thermal and hydric environments on hatching success, embryonic use of energy and hatchling traits in a colubrid snake, Elaphe carinata.

We examined the effects of thermal and hydric environments on hatching success, the embryonic use of energy and hatchling traits in a colubrid snake, Elaphe carinata. The eggs were incubated at four temperatures ranging from 24 to 32 degrees C on substrates with water potentials of 0 and -220 kPa using a 4x2 factorial design. Both thermal and hydric environments affected the water exchange between eggs and their surroundings. Eggs incubated in wetter substrates gained mass throughout the course of incubation, whereas eggs in drier substrates gained mass during the first half of incubation and lost mass thereafter. Hatching success was noticeably higher at 26 and 30 degrees C than at 24 and 32 degrees C, but among treatments, differences in hatching success were not significant. Temperature significantly affected the duration of incubation and most hatchling traits examined. Deformed hatchlings were found in all temperature treatments, with more deformities observed at 32 degrees C. Hatchlings from eggs incubated at different temperatures differed in wet body mass, but the differences stemmed mainly from variation in water contents. Embryos at different temperatures completed development at nearly the same expenditure of energy and catabolized nearly the same amount of lipids, but hatchlings from different temperatures differed in the development condition of carcass at hatching. Hatchlings from eggs incubated at 26 degrees C were larger in SVL than those from other higher or lower incubation temperatures, characteristically having larger carcasses; hatchlings from 32 degrees C eggs were smaller in SVL and had smaller carcasses but larger residual yolks than those from lower incubation temperatures. Hatchlings from eggs incubated at 24 degrees C were shorter in tail length but greater in size (SVL)-specific body wet mass than those from higher incubation temperatures. Within the range from -220 to 0 kPa, the substrate water potential did not affect hatching success, the embryonic use of energy and all hatchling traits examined, and the effects of temperature were independent of the effects of substrate water potential. Therefore, our data add evidence showing that embryonic development in reptiles with pliable-shelled eggs is relatively insensitive to variation in hydric environments during incubation.     

Incubation temperature affects hatching success,embryonic expenditure of energy and hatchling phenotypes of a prolonged egg-retaining snake,Deinagkistrodon acutus (Viperidae)

We used eggs of Deinagkistrodon acutus to study the effects of incubation temperature on hatching success, embryonic expenditure of energy and hatchling phenotypes. One egg from each of the 15 fertile clutches was dissected for determination of egg composition, and a total of 164 eggs were incubated at five constant temperatures. Embryonic mortality increased dramatically at 30 °C, and none of eggs incubated at 32 °C hatched. Within the range from 24 to 30 °C, temperature affected incubation length and most hatchling traits examined. The mean incubation length at 24, 26, 28 and 30 °C was 36.4, 28.7, 21.8 and 15.7 days, respectively. Embryos developing at higher temperatures (28 and 30 °C) consumed more energy but produced less developed (and hence smaller) hatchlings, which characteristically had larger residual yolks but smaller carcasses. A principal component analysis resolved two components (with eigenvalues ⩾1) from ten size (initial egg mass)-free hatchling variables, accounting for 79.3% of variation in the original data. The first component (43.8% variance explained) had high positive loading for size-free values of dry mass, lipid mass, energy contents and ash mass of hatchlings, and the second component (35.5% variance explained) had high positive loading for size-free values of SVL, carcass dry mass and fatbody dry mass. Hatchlings from different incubation temperatures did not differ in scores on the first axis of the principal component analysis, whereas hatchlings from higher incubation temperatures (28 and 30 °C) had significantly lower scores on the second axis than did those from lower incubation temperatures (24 and 26 °C). As the second axis mainly represents traits relating to the developmental condition at hatching, the analysis therefore provided further evidence that eggs incubated at higher temperatures produced less developed hatchlings. Taken together, our data show that the optimal temperatures for embryonic development are relatively low in D. acutus largely due to its use of relatively cool habitats.     

温度、湿度对黄喉拟水龟胚胎发育的影响

在9种不同温湿度组合条件（25 ℃和-12 kPa、29 ℃和-12 kPa、33 ℃和-12 kPa、25 ℃和-150 kPa、29 ℃和-150 kPa、33 ℃和-150 kPa、25 ℃和-300 kPa、29 ℃和-300 kPa、33 ℃和-300 kPa）下孵化了黄喉拟水龟卵,研究了温度对黄喉拟水龟卵孵出幼体特征的影响及其与湿度的相互作用对孵化期、孵化成功率和孵出幼体特征的影响.结果表明：黄喉拟水龟卵的初始质量、孵化温度、湿度及温湿度相互作用均显著影响孵化过程中卵质量的增加;同一温度下,孵化湿度越高,卵的终末质量越大;而孵化卵的终末质量与孵化温度并不呈线性相关;孵化温度显著影响黄喉拟水龟卵的孵化期,温度越高、孵化期越短,孵化湿度及温湿度相互作用对孵化期的影响不显著;孵化温度和湿度显著影响孵化成功率和卵壳龟裂率;25 ℃和33 ℃处理组孵出幼体中发现畸形个体,而29 ℃处理组中未发现;孵化温度显著影响孵出幼体的质量、背甲长和宽、腹甲长和宽、体高和尾长;孵化湿度只对孵出幼体的背甲长有影响,对其他被检测的幼体特征无显著影响;温湿度的相互作用对所有被检测的孵出幼体特征无叠加或减弱的显著影响.     

Phenotypic responses of hatchlings to constant versus fluctuating incubation temperatures in the multi-banded krait, Bungarus multicintus (Elapidae)

Most studies on egg incubation in reptiles have relied on constant temperature incubation in the laboratory rather than on simulations of thermal regimes in natural nests. The thermal effects on embryos in constant-temperature studies often do not realistically reflect what occurs in nature. Recent studies have increasingly recognized the importance of simulating natural nest temperatures rather than applying constant-temperature regimes. We incubated Bungarus multicintus eggs under three constant and one fluctuating-temperature regimes to evaluate the effects of constant versus fluctuating incubation temperatures on hatching success and hatchling phenotypes. Hatching success did not differ among the four treatments, and incubation temperature did not affect the sexual phenotype of hatchlings. Incubation length decreased as incubation temperature increased, but eggs incubated at fluctuating temperatures did not differ from eggs incubated at constant temperatures with approximately the same mean in incubation length. Of the hatchling phenotypes examined, residual yolk, fat bodies and locomotor performance were more likely affected by incubation temperature. The maximal locomotor speed was fastest in the fluctuating-temperature and 30 degrees C treatments and slowest in the 24 degrees C treatment, with the 27 degrees C treatment in between. The maximal locomotor length was longest in the fluctuating-temperature treatment and shortest in the 24 degrees C and 27 degrees C treatments, with the 30 degrees C treatment in between. Our results show that fluctuating incubation temperatures do not influence hatching success and hatchling size and morphology any differently than constant temperatures with approximately the same mean, but have a positive effect on locomotor performance of hatchlings.     

Influence of incubation temperature on morphology, locomotor performance, and early growth of hatchling wall lizards (Podarcis muralis)

Eggs of wall lizards (Podarcis muralis) were incubated at three temperatures approaching the upper limit of viability for embryonic development in this species (26, 29, and 32 degrees C) to assess the influence of temperature on various aspects of hatchling phenotype likely affecting fitness. The thermal environment affected size and several morphometric characteristics of hatchling lizards. Hatchlings from eggs incubated at 32 degrees C were smaller (snout-vent length, SVL) than those from 26 and 29 degrees C and had smaller mass residuals (from the regression on SVL) as well as shorter tail, head, and femur relative to SVL. Variation in the level of fluctuating asymmetry in meristic and morphometric traits associated with incubation temperatures was quite high but not clearly consistent with the prediction that environmental stress associated with the highest incubation temperatures might produce the highest level of asymmetry. When tested for locomotor capacity in trials developed at body temperatures of 32 and 35 degrees C, hatchlings from the 32 degrees C incubation treatment exhibited the worst performance in any aspect considered (burst speed, maximal length, and number of stops in the complete run). Repeated measures ANCOVAs (with initial egg mass as covariate) of snout-vent length and mass of lizards at days 0 and 20 revealed significant effects of incubation temperature only for mass, being again the hatchlings from eggs incubated at 32 degrees C those exhibiting the smallest final size. All together, our results evidenced a pervasive effect of thermal regime during incubation (and hence of nest site selection) on hatchling phenotypes. However, incubation temperature does not affect hatchling phenotypes in a continuous way; for most of the analysed traits a critical threshold seems to exist between 29 and 32 degrees C, so that hatchlings incubated at 32 degrees C exhibited major detrimental effects. J. Exp. Zool. 286:422-433, 2000.     

Comparisons of egg incubation and hatchling traits among captive cohorts of the Chinese three-keeled pond turtle, Chinemys reevesii

Freshly-laid eggs of the Chinese three-keeled pond turtle (Chinemys reevesii) from captive cohorts in Hunan, Shanghai and Jiangxi were incubated at four constant temperatures of 24, 26, 28 and 30 °C to assess the effects of incubation temperature and cohort origin on incubation duration and hatchling phenotypes. Eggs from the three cohorts differed in size and shape. Egg mass and width were greatest in the Hunan cohort, smallest in the Jiangxi cohort, with the Shanghai cohort in between. Incubation duration decreased with increasing temperature and differed among the cohorts, with longer incubation duration for eggs from the Jiangxi cohort than those from the Hunan or Shanghai cohorts. Incubation temperatures significantly affected hatchling size and hatchlings from 30 °C were smaller than those from the lower temperatures in terms of carapace size and body mass. When incubated at a common temperature, hatchlings from the Hunan and Shanghai cohorts were larger than those from the Jiangxi cohort. The swimming capacity of hatchlings was affected by incubation temperature, but did not differ among the cohorts. The characteristics of eggs and hatchlings were similar among the Hunan and Shanghai cohorts, but they differed significantly from the Jiangxi cohort.