There are 80 or more species of eels of the family Muraenidae.
Moray eels occur in all tropical and subtropical seas.
They live in shallow water among reefs and rocks and hide in crevices. They differ from other eels in having small rounded gill openings and in generally lacking pectoral fins. They are apt to attack humans only when disturbed, but then they can be quite vicious. Moray eels are usually vividly marked or colored. Morays are eaten sometimes, but their flesh is often toxic and may cause sickness or death.