testacean

例句：

1. 1. The testacean is a marine creature that lives in the ocean.
   海胆是一种生活在海洋中的生物。
2. 2.Sea turtles are protected by international law and play an important role in ecosystems.
   海龟受到国际法律保护，在生态系统中扮演着重要角色。
3. 3.The testacean's shell is a unique feature that distinguishes it from other marine creatures.
   海胆的壳是一个独特的特征，与其他海洋生物区分开来。