入侵物种福寿螺卵斑性状在纬度间的变异

Variation of egg spot traits of Pomacea canaliculata,an invasive species across latitudes

于2015年6—10月采集了18°N—28°N共计11个纬度的福寿螺(Pomacea canalicu-lata)卵斑,调查基本覆盖福寿螺在中国的南北分布界限,对各纬度卵斑的长、宽、高、重量、体积、卵粒数量和卵粒直径进行了测量,对所测量的卵斑性状在纬度间的差异进行了单因素方差分析,各纬度卵斑性状与卵粒数量进行了逐步回归分析。结果表明:跨所有纬度,卵斑的长度、宽、高、重量和体积分别为20~60 mm、10~26 mm、6.5~18 mm、0.6~5.1 g、1.0~7.0 cm^3,均值分别为35.94 mm、15.12 mm、10.53 mm、1.9 g、3.0 cm^3;每块卵斑的卵粒数量为81~621粒,卵粒数集中在110~400,平均卵粒数为279粒·块^(-1),卵粒直径在1.35~3.00mm,平均直径为2.16 mm;福寿螺卵斑长、宽、高和体积在纬度间无显著差异性;卵斑重量及卵粒数在纬度间存在显著差异,高纬度地区卵斑重量和卵粒直径相对较大;逐步回归分析表明,不同纬度预测福寿螺卵粒数量需要不同的卵斑性状特征,19°N需要宽和体积两个表型性状;20°、21°N则只需要体积一个表型性状;25°、26°、27°N则只需要卵斑重量一个表型性状;跨所有纬度需要长(x_1)、宽(x_2)和体积(x_3)3个卵斑性状共同预测卵斑的卵粒数量(y),预测公式:y=3.897x_1+9.042x_2+46.152x_3-135.044。本研究能够为将来探讨福寿螺繁殖特性在空间上的变异特征及其对环境的适应性提供一定的借鉴,为针对性开展福寿螺的分布预测及防控工作提供参考。

We collected the egg spots of golden apple snails （Pomacea canclieulata） across 11 latitudes （ 18°N to 28°N） during June to October 2015, which covered the major colonized areas from north to south boundaries in China. We measured the length, width, height, weight, volume of egg spots, and the diameter and number of eggs across latitudes, and analyzed the differences of these traits among latitudes and their relationship with latitude using step regression method. The results indicated that across all latitudes, the egg spot length, width, height, weight and volume were 20-60 ram, 10-26 mm, 6.5-18 mm, 0.6-5.1 g and 1.0-7.0 cm3, with mean values of 35.94 mm, 15.12 mm, 10.53 mm, 1.9 g and 3.0 cm2, respectively. The egg number of each egg spot was 81-621, with an average number of 279. Egg diameter ranged from 1.35 mm to 3.00 mm and the mean diameter was 2.16 mm. There were no significant differences in egg spot length, width, and height among latitudes, while significant differences were observed in egg spot weight and the egg number of each egg spot among latitudes. There were greater egg spot weight and egg diameter at the high latitudes than at the low latitudes. The step regression indicated that, to predict egg number of apple snails at different latitudes, different egg spot traits were needed. For example, the number of eggs could be predicted by egg spot width and volume at 19° N, while only egg spot volume could be used for 20° and 21°N, and egg spot weight could be used for 25°, 26~ and 27°N. Generally, the egg spot length （x1）, width （x2） and volume （x3） were needed in better predicting egg number （y） across different latitudes by using the following formula： y=3.897x1＋9.042x2＋46.152x3-135.044. This study provided insights into the spatial variation of reproduction characters, reproduction adaptation and biological control of P. canalicu- lata colonized in China.