石灰氮对福寿螺的急性毒性效应

Acute toxic effect of calcium cyanamide on golden apple snail (Pomacea canalic ulata)

福寿螺(Pomacea canaliculata)是世界自然保护联盟认定的世界100种恶性外来入侵物种之一,在华南地区已对水稻生产造成严重危害。本研究将福寿螺按照壳高(H)分为小螺(5mm≤H<15mm)、中螺(15mm≤H<25mm)、大螺(25mm≤H<35mm)和超大螺(35mm≤H<45mm),通过室内毒性试验,探讨了化学肥料石灰氮(氰氨化钙)对不同体型福寿螺的毒性效应。结果表明:石灰氮对不同大小福寿螺毒性效应显著,尤其是对中小福寿螺具有很强的抑制和杀灭作用;石灰氮处理7d后,最低浓度0.2g·L-1处理造成71%死亡率,其他处理死亡率均在95%以上,其中3.0和5.0g·L-1处理中福寿螺全部死亡;石灰氮对不同大小福寿螺的半抑制浓度(24h)和半致死浓度(96h)大小顺序均为小螺<中螺<大螺<超大螺;石灰氮对福寿螺的抑制效应显著,其对福寿螺的平均半抑制浓度为0.08～0.39g·L-1;1.0和5.0g·L-1浓度的石灰氮处理24h后,福寿螺鰓组织SOD酶活性呈极显著下降,分别为对照的41%和60%。本研究表明,石灰氮在入侵生物福寿螺的防治方面有一定应用潜力,有望成为一种新型的"杀螺肥料"。

Golden apple snail （Pomacea canaliculata） is one of the 100 worst inva sive alien species cognized by World Conservation Union,and has been resulting in a mass loss of rice production in South China.In this study,the snails acco rding to their shell height （H） were divided into four groups,i.e.,small s ize （5 mm≤H15 mm）,medium size （15 mm≤H25 mm）,large size （25 mm≤H35 mm）,and extra large size （35 mm≤H45 mm）,and a laboratory toxicity test was conducted to evaluate the molluscicida l activity of chemical fertilizer calcium cyanamide （CaCN2） in controlling dif ferent sizes P.canaliculata.Calcium cyanamide had significant molluscicida l effect on different sizes,especially small and medium s izes P.canaliculata.After treated one week,0.2 g·L-1 of CaCN2 in duced 71% mortality,and high concentrations CaCN2 resulted in above 95% morta lity,with 100% mortality in treatments 3.0 g·L-1 and 5.0 g·L-1 of CaCN2.Both the 24 h median inhibitive concentration and the 96 h medi an lethal concentration of CaCN2 on different sizes P.canaliculata were a ll in the order of small size medium size large size extra large size.Cal cium cyanamide had significant inhibitive effect on P.canaliculata.The mea n inhibitive concentration of CaCN2 ranged from 0.08 g·L-1 to 0.39 g·L-1.After treated 24 h,the SOD activity of P.canaliculata in treatments 1.0 g·L-1 and 5.0 g·L-1 of CaCN2 decrea sed significantly,being 41% and 60% of the control,respectively.This study sh owed that calcium cyanamide had definite potential in controlling P.canalicul ata invasion,being hopeful to be used as a kind of molluscicidal fertilizer i n paddy field.