Apterygiformes

例句：

1. 1.Apterygians are a group of fish that live in the oceans.
   鳍鱼是生活在海洋中的一类鱼类。
2. 2.The apterygians are known for their unique adaptations to their environment.
   鳍鱼因其独特的适应环境而闻名。
3. 3.Apterygians are an important part of the ecosystem, providing food and shelter for other animals.
   鳍鱼是生态系统中的重要部分，为其他动物提供食物和庇护所。