mussel

Paul is then left to choose one box to open to retrieve the mussel.

然后让保罗选择打开其中一个箱子来获得贻贝。

Pisaster has everted its stomach out through its mouth, and it'sdigesting the mussel externally.

海星通过嘴部把胃翻了出来，它正从外部消化这只贻贝。

In the shallows, the dark, water-soakedsticks and twigs, smooth and old, were undulating in clusters on the bottomagainst the clean ribbed sand, and the track of the mussel was plain.

滩头水浅处，湖底沙地干净整洁，纹路层叠，贻贝爬过的痕迹清晰可辨，另有长短不一的枝桠成簇在水底摇摆不定，或光滑或腐朽，一律给湖水浸得发乌。