holacanth

例句：

1. 1. The seaurchin is a small marine creaturewith a hard shell.
   海胆是一种小型的海洋生物，有硬壳。
2. 2. Sea cucumbers are often used in traditional Chinese medicine.
   海参在传统中医中常被使用。
3. 3. Thesea urchin's venom is highly toxic and can cause severepain.
   海胆的毒液非常有毒，会引起剧烈疼痛。