1. Appearance: Hookfish looks like a long snake, but its body is relatively thick and presents a diamond shape, while eel's body looks like a long snake, but it is usually scaleless.
2. Living habits: Hookfish usually inhabit rivers, lakes and other waters, and is a bottom fish. Eels, on the other hand, live in the sea area where salt and fresh water meet, and have migratory characteristics.
Generally speaking, hook fish and eel are two kinds of fish with different characteristics, which can be distinguished according to observation and practice.