The Moray Eel Is a True Eel, Unlike Electric Imposters

Moray eels belong to the family Muraenidae and are true eels, distinct from other eels (like electric eels) thanks to several anatomical features.

Unlike most fish, they lack pectoral and pelvic fins, and instead have elongated dorsal, anal and caudal fins that run along their body. This gives morays a laterally compressed, ribbon-like appearance that helps them slither through tight reef crevices.

Morays also possess pharyngeal jaws — a second set of jaws within their throat that can reach forward to grip slippery prey like fish and crustaceans. Combined with large teeth and powerful upper jaws, this makes them skilled predators in shallow water environments.

Because of the risk of ciguatera poisoning, moray eel meat is generally not consumed by humans.

Moray eels inhabit coral reefs, seagrass beds, rocky crevices and even sand dwelling areas throughout warm oceans. You’ll find species of moray along the western Atlantic Ocean, northern Gulf of Mexico, and across the Indo-Pacific.

Large green morays (Gymnothorax funebris) are common in the Caribbean and can grow up to 8 feet (2.4 meters) long.

The giant moray (Gymnothorax javanicus), one of the largest morays, dominates reefs in the Indian and Pacific Oceans.

Then there's the colorful ribbon eel and the distinctive zebra moray (Gymnomuraena zebra) with molar-like teeth for crushing crustaceans.

The green appearance of many morays, such as green moray eels (Gymnothorax funebris), comes from a yellowish mucus layer covering their skin, which is actually brownish or dark blue underneath. This slimy coating protects them from abrasions as they navigate rocky environments.

Because they have poor eyesight, morays rely on a keen sense of smell to detect prey. As nocturnal predators, they often hunt smaller fish, crabs and other invertebrates under cover of darkness.

Some species, like the snowflake moray (Echidna nebulosa), specialize in eating hard-shelled prey with their molar-like teeth.

Many morays are solitary, hiding in rock crevices or seagrass beds by day and hunting at night. They often cooperate with cleaner shrimp, opening their mouths wide to allow the shrimp to remove parasites — a mutualistic relationship beneficial to both species.

Despite their menacing look, moray eels have few natural predators. Larger fish, sharks and humans are among the few threats they face. Still, their slippery form and hiding habits make them a challenging catch.

Scuba divers frequently spot morays peeking from reefs, especially in the Caribbean and Indo-Pacific. While they’re not typically aggressive, morays can bite if provoked or startled, often resulting in deep wounds thanks to their large teeth and strong jaws.

Moray eels begin life as leptocephalus larvae — tiny, transparent, leaf-like creatures that drift in the open ocean for months before settling into reefs. This planktonic stage allows them to disperse across wide geographic ranges.

Their reproduction is not well-studied, but many species are believed to spawn in the open ocean, making juvenile morays hard to track. As they grow, their habitats narrow to reef and rocky environments where they become key predators.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.