Any of numerous aquatic or terrestrial mollusks of the class Gastropoda, typically having a spirally coiled shell, broad retractile foot, and distinct head.

蜗牛：腹足科众多水生或陆栖软体动物中的一种，通常带有一螺旋似的厚壳，足宽且向内旋，脑袋清晰。

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Few species, low biomass and lack of blue green algae, Gastropoda, Lamellibranchia and Crustacea are most notable characteristics distinguished from general neutral and alkaline lakes.

湖泊生物种群少且生物量低，缺失蓝藻和腹足类、瓣鳃类、甲壳类动物等为其区别于一般中、碱性湖泊最显著的特点。

youdao

Few species, low biomass and lack of blue green algae, Gastropoda, Lamellibranchia and Crustacea are most notable characteristics distinguished from general neutral and alkaline lakes.

湖泊生物种群少且生物量低，缺失蓝藻和腹足类、瓣鳃类、甲壳类动物等为其区别于一般中、碱性湖泊最显著的特点。

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