Echinidae

例句：

1. 1. The echinoderms arefound in the oceans and seasaround the world.
   棘皮动物在世界各大海洋和海域中都有分布。
2. 2. Echinus is a species of sea urchin that lives in the deep sea.
   海胆是生活在深海的一种海生无脊椎动物。
3. 3. Echinoidea is agroup of echinoderms thatincludes sea urchins and starfish.
   棘皮动物亚纲包括海胆和星鱼等棘皮动物。