The evolution from fin to limb took millions of years. 从鳍到肢的进化用了数百万年
Vezh fin saja rhaesheseres! [多斯拉克语 ]
a modified dorsal fin, 是一种改良后的背鳍
never wasting a fin stroke. 从不贸然浪费力气
A dumbo octopus simply flaps a fin 小飞象章鱼拍打翅膀来游泳