生活在河流或湖泊底部的软体动物。藏身在坚硬的外壳中，通过滤水摄取食物，一旦受到威胁，便会迅速闭壳自保。
A mollusk that lives buried in the bottom of rivers or lakes. Inside its hard shell, it sifts water to obtain food, and when threatened, snaps shut tight to keep itself safe.
生活在河流或湖泊底部的软体动物。藏身在坚硬的外壳中，通过滤水摄取食物，一旦受到威胁，便会迅速闭壳自保。
A mollusk that lives buried in the bottom of rivers or lakes. Inside its hard shell, it sifts water to obtain food, and when threatened, snaps shut tight to keep itself safe.