四川地区外来生物福寿螺的繁殖力

Fecundity of exotic golden apple snail,Pomacea canaliculata,in Sichuan

于2012年3—10月每月定期采集四川雅安地区3种生境（水库、稻田、沟渠）福寿螺卵块，采用野外采卵和室内繁殖的方法研究了福寿螺的繁殖力。结果表明：野外福寿螺卵块单块卵粒数差异较大，在33～621粒·块-1，平均为233粒·块-1，变异系数（CV）55.0%，卵粒直径差异较小，在2.17～3.20 mm，平均为2.60 mm，变异系数（CV）8.95%。福寿螺卵块重与卵粒数呈极显著正相关（P＜0.01）；福寿螺5月绝对繁殖力最高，为403.1粒·块-1，与其他月份之间存在显著性差异（P＜0.05）；3种生境中，水库生境福寿螺绝对繁殖力最高，与稻田和沟渠两种生境存在显著性差异（P＜0.05）；对采集自成都、雅安、资阳三地水库中福寿螺，应用单对交配的方法进行室内繁殖研究其相对繁殖力，3个地区福寿螺的相对体重繁殖力分别为12.33、9.58和10.54粒·g-1，相对壳高繁殖力分别为4.55、3.92、3.54粒·mm-1，3地区间相对繁殖力没有显著性差异。本研究初步弄清了四川地区福寿螺的繁殖规律，为福寿螺的防治提供一定的科学依据。

Egg masses of Pomacea canaliculata were collected monthly from three habitats including reservoir, rice field, and irrigation canals and ditches in Ya＇an, Sichuan Province from March to October 2012 and the fecundity of P. canaliculata was studied by using the methods of collecting snail eggs in the fields and breeding in the laboratory. The field investigation results indicated that egg numbers per egg mass varied distinctly, ranging from 33 to 621 individual eggs per mass （an average of 233 individual eggs per mass） with a coefficient of variation （CV） of 55.0%. The egg diameter ranged from 2.17 to 3.20 mm （mean = 2.60 mm, CV = 8.95%）. The number of eggs was significantly positively correlated with the weight of egg mass （P〈0.01）. The absolute fecundity value of P. canaliculata in May was the highest （403.1 eggs·mass-1）, and significantly different （P〈0.05） from those in the other months. The absolute fecundity from the reservoir was higher （P〈0.05） than from rice field and irrigation canals and ditches. Meanwhile, a comparative study on the fecundity of P. canaliculata collected from Chengdu, Ya＇an and Ziyang was also conducted by using the singlepair mating method in the laboratory. The results showed that the individual relative fecundity values from the three areas were 12.33, 9.58 and 10.54 eggs per gram of snail body weight, and 4.55, 3.92 and 3.54 eggs per millimeter of the snial shell height, respectively. The individual relative fecundity values of P. canaliculata from the three areas were not significantly different. Our work would provide a preliminary understanding for the reproductive characteristics of P. canaliculata in Sichuan and offer a scientific reference for snail prevention and control.