Trepang

1. Any one of several species of large holothurians, some of which are dried and extensively used as food in China; -- called also bêche de mer, sea cucumber, and sea slug.
   

The edible trepangs are mostly large species of Holothuria, especially Holothuria edulis. They are taken in vast quantities in the East Indies, where they are dried and smoked, and then shipped to China. They are used as an ingredient in certain kinds of soup.