Most eels live in the shallow waters of the ocean and burrow into sand, mud, or amongst rocks. A majority of eel species are nocturnal and, thus are rarely seen. Sometimes, they are seen living together in holes, or "eel pits". Some species of eels also live in deeper water on the continental shelves and over slopes as deep as 4,000 m (13,000 ft). Only members of the Anguilla regularly inhabit fresh water, but they, too, return to the sea to breed.

Based on TCM, eel can be used to:

1. supplements qi and yang
2. regulates wind and dampness

The preparation methods of eel are fried, boiled, or in soup.

Eel contains protein, high-fat content, calcium, and phosphorus.

Some indications that can be reduced by eel are:

  * Qi and yang vacuity: weakness, exhaustion, shortness of breath.

  * Wind and dampness disorders: pain and swelling in extremities, weakness in legs and hips (rheumatic complaints caused by wind–dampness).