pin-fins tube

例句：

1. 1.The pin-fins tube is a crucial part of the fish's skeleton.
   鱼鳍管是鱼骨骼中至关重要的部分。
2. 2. The fish uses its pin-fins tube to navigate through the water.
   鱼使用它的鱼鳍管在水中导航。
3. 3.The pin-fins tube helps the fish to swim efficiently.
   鱼鳍管帮助鱼类高效游泳。