湖北钉螺指名亚种与滇川亚种半数冬眠温度差异的实验研究

Differences on hibernating temperature between Oncomelania hupensis hupensis and O.h.robertsoni

目的 比较湖北钉螺指名亚种与滇川亚种对低温的适应性差异。方法 野外分别采集江西省星子县新池乡的湖北钉螺指名亚种和四川省天全县新华乡的滇川亚种钉螺,选取经逸蚴法检测为阴性且活力好的成体螺为研究对象,在冬季将其置于人工气候箱中饲养,起始饲养温度为13℃,按1℃/2d的速率逐渐降低饲养温度,直至0℃。饲养温度每降低1℃,各取出一组钉螺测定其冬眠率及死亡率;另以湖北钉螺指名亚种为对象,用上述方法,在次年夏季重复实验。采用Probit回归分析方法分别计算两亚种、冬夏两季的半数冬眠温度（ET50）并对其差异性进行比较。结果 四川省天全县的湖北钉螺滇川亚种与江西省星子县的湖北钉螺指名亚种的ET50及95%可信区间分别为0.483℃（-0.440℃~1.332℃）和2.435℃（1.695℃~3.146℃）,两亚种ET50的95%的可信区间无重叠,有统计学差异;江西省星子县的湖北钉螺指名亚种在夏季和冬季的ET50及95%可信区间分别为2.046℃（1.331℃~2.745℃）和2.780℃（2.094℃~3.532℃）,两者ET50的95%可信区间有重叠,无统计学差异。结论 湖北钉螺滇川亚种与指名亚种的ET50存在差异,湖北钉螺指名亚种夏季与冬季的ET50无差异。

To compare the differences of adaptability to low temperature between Oncomelania hupensis （0. h） hupensis and O. h. robertsoni, snails named O. h. hupensis and O. h. robertsoni were collected from areas of Xingzi County in Jiangxi Province, China（GPS： N 29°26＇32＂E 115°57＇40＂） and Tianquan County in Sichuan Province, China（GPS： N 30°06＇36＂E 102° 52~52＂）, respectively. Oncomelania hupensis which were vibrant and negative in escaping cercariae test were chosen in our study. The two strains of snails were placed in artificial climate chamber and decreased to 0 ℃ with 1 ℃ / 2 day rate gradually beginning from 13 ℃, while detecting the hibernation rate and the death rate of two strains of snails at each temperature point. The same experiment settings were applied on O. h. hupensis in next summer. The ET50 between two strains from two seasons were then compared. Results showed that the hibernation temperature of 50% O. h. robertsoni was 0. 483℃ （950//00 confidence interra[ from -0. 440℃-- 1. 332℃） and O. h. hupensis was 2. 435℃ （95% confidence interral from 1. 695 ℃ --3. 146 ℃ ）. No overlapping was detected between the 95% confidence interval of the two strains. However, there was a significant difference in the hibernating temperature within this range. But the hibernation temperature of 50%. h. hupensis in summer was 2. 046 ℃ （95% confidence interval {total. 331℃ --2. 745 ℃ ） and 2. 780 ℃ （95% confidence interval from 2. 094℃--3. 532 ℃） in winter. Overlapping existed in the 95% confidence interval of the two groups. There was no significant difference between the two hibernating temperature within this range. There is no statistically significant difference in the hibernating temperature of O. h. hupensis and O. h. robertsoni. There is no statistically significant difference in hibernating temperature of O. h. hupensis in summer and in winter.