water beetle
noun
1- any of a large number of beetles that live in fresh water水生甲虫。
1.1
- Several families, in particular Dytiscidae (the predatory diving beetles) and Hydrophilidae (scavenging beetles).数科, 尤指龙虱科（食肉性龙虱）和水龟虫科（食腐甲虫）。