摘要
用恒温 (2 4、2 7、3 0和 3 3℃ )和波动温度 (平均 2 6.1℃ ,范围 2 0 .1～ 3 2 .7℃ )孵化虎斑颈槽蛇 (Rhabdophistigrinuslateralis)卵 ,检测热环境对孵化期、孵化成功率和孵出幼体的影响。孵化热环境显著影响孵化期、孵化成功率和胚胎畸形率 ,对孵出幼体性别无显著影响。孵化期随孵化温度升高而缩短 ,2 4、2 7、3 0和 3 3℃的平均孵化期分别为 45 .0、3 2 .7、2 7.3和 2 6.0 d,波动温度的平均孵化期为 3 7.9d。3 3℃孵化成功率最低 (1 6.7% ) ,胚胎畸形率最高 (1 0 0 % )。孵出幼体总性比 (雌性 /雄性 =0 .6)不显著偏离 1 :1。孵出幼体的尾长显示两性异形 ,雄性尾长大于雌性 ;其它被检幼体特征无显著的两性差异。 2 4、2 7和 3 0℃以及波动温度孵出幼体的所有被检指标均无显著差异。 3 3℃孵出幼体的体重和个体大小小于其它热环境中孵出的幼体 ,并特征性地具有较小的躯干、较大的剩余卵黄。 3 3℃中胚胎发育的能耗显著大于其它热环境中胚胎发育的能耗。 3 3℃孵出幼体的灰分含量较低 ,但孵出卵卵壳较重。 3 3℃孵出幼体不能运动 ;其它热环境中孵出的幼体在跑道上表现良好 ,这些幼体的不间断运动的最大距离、每分钟运动距离和每分钟停顿次数无显著的差异。结果表明 ,持续将虎斑颈槽蛇卵暴露在 3 3℃?
We incubated Rhabdophis tigrinus lateralis eggs laid by 12 females at constant (24, 27, 30, and 33 ℃) and fluctuating (mean = 26.1 ℃, range=20 1～32 7 ℃) temperatures to assess the effects of thermal environments on incubation length, hatching success, and hatchling traits. Eggs were incubated at the same moisture level (2 g water / 1 g vermiculite; producing approximately\|12 kPa water potential in different thermal environments in plastic containers (250mm×180mm×70mm) that were covered with a perforated plastic membrane. Eggs were 1/3\|buried in the substrate, with the surface near the embryo exposed to air inside the container. We weighed containers daily and, if necessary, added water to the vermiculite to compensate for small evaporative losses and water absorbed by eggs. Eggs were weighed at 5\|day intervals. Upon emergence, each hatchling was weighed, examined for locomotor performance, and then killed by freezing to -15 ℃ for later studies. Because locomotor performance is highly sensitive to changes in body temperature in reptiles, we conducted trials at constant body temperature of 30 ℃. Body temperature of hatchlings was controlled by placing them in an incubator at 30 ℃. Locomotor performance was assessed by chasing hatchlings along a round racetrack of which the circumference was 1.92 m, which allowed vertical filming with a digital video camera. Videotapes were examined for time specific number of stops, time specific locomotor distance, and maximum continuous locomotor distance traveled without stopping during the entire trial. The frozen hatchlings were later thawed for data collection. Sex of hatchlings was determined by pressing on both sides of the tail base using forceps for the presence or absence of hemipenes. SVL (snout vent length) and tail length were measured for each hatchling. After taking the measurements, each hatchling was separated into carcass, fat bodies, and residual yolk. The three components were dried in an oven at 65 ℃ to constant mass, and then weighed. We extracted non polar lipids from dried samples in a Soxhlet apparatus for a minimum of 5 5 h using absolute ether as solvent. The amount of lipids in a sample was determined by subtracting the lipid free dry mass from the total sample dry mass. We determined energy density of dried samples using an adiabatic bomb calorimeter. Ash in samples was determined using a muffle furnace at 700 C for a minimum of 12 h. All data were tested for normality using Kolmogorov\|Smirnov test, and for homogeneity of variances using Bartlett's test. Log\-e or arc sine transformations were performed when necessary to satisfy the conditions for using parametric tests. We use linear regression analysis, one and two factor analyses of variance (ANOVA), and one and two factor analyses of covariance (ANCOVA), when the assumptions of parametric analyses were met. Nonparametric analyses were used when these assumptions were violated. Throughout this paper, values are presented as mean±1 standard error, and the significance level is set at α =0.05. Incubation length, hatching success and the incidence of deformed embryos were affected by incubation thermal environments, and the sex ratio of hatchlings was not. Incubation length decreased dramatically as temperature increased. The average duration of incubation at 24, 27, 30 and 33 ℃ was 45 0, 32 7, 27 3 and 26 0 d, respectively; the duration of incubation at fluctuating temperatures averaged 37 9 d. Hatching success was the lowest (16 7%) at 33 ℃, but the highest incidence (100%) of deformed embryos was recorded from eggs incubated at this temperature compared to eggs incubated in other thermal environments. The overall sex ratio of hatchlings did not differ from equality. Except for that males had longer tails than did females, all other examined hatchling traits did not differ between both sexes. Hatchlings from eggs incubated at 24 ℃, 27 ℃, 30 ℃ and fluctuating temperatures did not differ in any of the examined traits. Hatchlings from eggs incubated at 33 ℃
出处
《生态学报》
CAS
CSCD
北大核心
2002年第11期1850-1858,共9页
Acta Ecologica Sinica
基金
浙江省自然科学基金青年人才专项基金资助项目
关键词
热环境
虎斑颈槽蛇卵
孵化期
孵化成功率
孵出幼体
性别
Colubridae
Rhabdophis tigrinus lateralis
egg
incubation
hatchling
locomotor performance
