| 摘要: |
| 于1997年10月，采用单个体培养方法，在15℃、20℃、25℃和30℃下对采自武汉东湖的壶状臂尾轮虫的实验种群动态进行了研究。结果表明，随着温度的升高，壶状臂尾轮虫各主要发育阶段如胚胎发育、生殖前期、生殖期、生殖后期等的历时，以及平均寿命均缩短，轮虫存活率下降的速度逐渐加快，繁殖率高峰值出现的时间逐渐前移。其中胚胎发育时间（D）和温度（T）间的回归方程式为：lnD＝11.66723–4.26479lnT+0.426203(lnT)2。在25℃时，壶状臂尾轮虫的产卵量显著高于其它各温度下的产卵量，种群的净生殖率和内禀增长率最大，因此该温度是壶状臂尾轮虫种群增长的最适温度。 |
| 关键词: 壶状臂尾轮虫 温度 种群动态 |
| DOI：10.11693/hyhz200001004004 |
| 分类号: |
| 基金项目:中国科学院重大项目资助,KY95－11 |
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| EFFECT OF TEMPERATURE ON THE EXPERIMENTAL POPULATION DYNAMICS OF BRACHIONUS URCEOLARIS |
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XI Yi-long, HUANG Xiang-fei
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Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, 430072
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| Abstract: |
| The effect of temperature on the experimental population dynamics of the rotifer, Brachionus urceolaris, obtained by hatching its resting eggs in sediment from Lake Donghu and clonal culture in October, 1997,was studied at 15°C, 20°C, 25°C, and 30°C. The 1–2 hour-old amictic females were grown individually in a suspension (0.5ml culture volume) of Chlorella ellipsoidea algae, in slight excess quantity. Observations were made every 4–8h for the appearance of eggs and neonates which were counted and removed. The rotifers were transferred to new suspensions daily. Following a number of methods, the durations of the principle developmental stages, the mean number of eggs produced by the rotifers and the parameters of population growth of the rotifer were calculated. The results show that with the temperature increasing from 15°C to 20°C, 25°C, and 30°C, the durations of embryonic development are shortened from 26.00h to 15.33h, 11.67h, and 8.67h, respectively. The durations of pre-reproductive period are decreased from 55.333h to 33.000h, 24.667h and 13.667h, respectively. The durations of reproductive period are reduced from 188.000h to 173.333h, 111.333h and 88.667h, respectively. The durations of postreproductive period are shortened from 62.000h to 55.333h, 36.667h and 18.000h, respectively. The mean lifespans of the rotifer are decreased from 305.333h to 261.667h, 172.667h and 120.333h, respectively. As the temperature rises the survival rate of rotifers decreases progressively and the reproductive peaks occur earlier. The curvilinear logarithmic equation of the relationship between the embryonic developmental time (day) and the temperature(°C) is : lnD＝11.66723–4.26479lnT+0.426203(lnT)2。
At 25°C, the mean number of eggs produced by the rotifer during its life net reproductive rate and intrinsic rate of increase of population are 24.8333 ind., 24.50 ind., and 0.045854h-1, respectively, and are the highest among all the studied temperatures. Hence, this temperature is optimal for population growth of Brachionus urceolaris. |
| Key words: Brachionus urceolaris, Temperature, Population dynamics |
