Ascidiacea

例句：

1. 1.The ascidiacea are found in the deep sea, where they feed on small fish and plankton.
   海鞘纲生物生活在深海，以小鱼和浮游生物为食。
2. 2. Ascidiacea play a crucial role in the marine ecosystem by filtering out harmful substances from the water.
   海鞘纲在海洋生态系统中起着至关重要的作用，它们通过过滤水中的有害物质。
3. 3.Scientists have discovered new species of ascidiacea that can be used for biomedical research.
   科学家们发现了新的海鞘纲物种，可用于生物医学研究。