pycnostachous

例句：

1. 1. The pycnostachous worm is a type of earthworm that lives underground.
   蚯蚓是一种生活在地下的蚯蚓。
2. 2. The pycnostachous worm is an important part of the ecosystem.
   蚯蚓是生态系统中的重要部分。
3. 3. The pycnostachous worm helps to break down organic matter in the soil.
   蚯蚓有助于土壤中的有机物质分解。