Moray Eel

When most people think of a moray eel, they think of a huge, secretive eel with tiny, cold eyes and jaws full of impressive fangs. But did you know there are over 200 species of these eels, and they live primarily in marine environments, from shallow reefs to deeper ocean waters, with only a few species occasionally found in brackish or estuarine habitats? Read on to learn more about these spectacular creatures.

Classification and Scientific Name

Moray eels belong to the Muraenidae family. The name comes from mūrēna, which is Latin for the Mediterranean moray eel. This word in turn comes from the Greek word muraina. There are 16 genera and over 200 species.

Appearance

The moray has a long, laterally compressed body and is scaleless. These eels have a long dorsal fin that can run the length of their back, but they lack pelvic and pectoral fins. They have long snouts with tiny nostrils, and the type of teeth in the jaws depends on the diet. Some of these fish have two rows of teeth in their top jaw. The California moray has teeth in the roof of its mouth that help it grip prey firmly, assisted by its pharyngeal jaws. Some morays have teeth that are pointed and curved, while others have teeth that resemble human molars. These teeth evolved in morays that need to crush the shells of crustaceans. All moray eels have pharyngeal jaws that shoot into the mouth — rather like a Xenomorph — to help hold onto prey.

Besides this, moray eels come in many sizes, from the diminutive, 4.5-inch-long Snyder’s moray eel to the 13-foot slender giant moray eel. The eels also come in a variety of colors and patterns, but they lack scales and protect their skin with a thick mucus layer, which in some species may contain toxins. Their eyes are small and don’t see well, so they depend largely on their sense of smell. This is fine, as most moray eels are nocturnal.

Types of Moray Eels

There are over 200 different types of moray eels in the world. These are just a few of them!

Giant Eel

Also called the red moray, the giant moray eel, Gymnothorax javanicus, isn’t the longest of the morays, for that title belongs to the slender giant moray. However, it is the heaviest. It is a large animal that can weigh as much as 66 pounds and grow to nearly 10 feet in length. Its body is usually brown, but red individuals have been seen, and adults have black spots in the area behind their heads. It is found in the Indo-Pacific area and can range from Hawaii to southern Japan. It is found in coral reefs and lagoons and spends most of its days hidden in crevices up to 164 feet deep.

Green Moray Eel

The green moray eel, Gymnothorax funebris, isn’t actually green. Its skin is either dark brown or gray, but the mucus secreted by the skin is yellow, which gives the eel a green color. A large green moray can be over 8 feet long and weigh nearly 64 pounds, but most of them are around 6 feet and weigh about 30 pounds. In contrast to the giant moray, the green moray is found in the western part of the Atlantic Ocean and the Caribbean and can be found from New Jersey south to Brazil. This eel lives in coral reefs, harbors, mangroves, and other intertidal areas.

Here are a few more of them:

• Muraena – The Muraena Eel is a large version of the Moray Eel, with 12 species. They can be found around coral reefs in the Mediterranean Sea. They are known for their bright colors.
• Dragon Moray Eel – Dragon Moray Eel, also known as the Leopard Moray Eel, can be found throughout a large stretch of the Indo-Pacific Ocean. Living up to its different names, this eel has striking, bright stripes on its head.
• Yellow-edged Moray Eel – Yellow-edged Moray Eels live in a similar area of the ocean as their dragon cousins, except that they typically live at deeper depths. Not as colorful as some other morays, these eels have a dull yellow coloration.

Distribution, Population, and Habitat

Moray eels are found in warmer waters all over the world. They thrive in both shallow waters and relatively deeper, benthic areas of the oceans. Though scientists don’t know their exact numbers, moray eels are especially numerous in habitats that offer them cover, such as those with rock formations or crevices.

The actual population of moray eels is unknown, but scientists do know that of the millions of eggs released during the spawning period, few hatch, and even fewer larvae reach maturity. As of 2022, the conservation status of most moray eels is least concern.

Predators and Prey

The largest of the moray eels are most likely the apex predators in their areas, but moray eels are prey for fish such as barracudas and sharks. Humans also kill moray eels, as do sea snakes. Moray eels prey upon smaller fish, crustaceans, and octopuses. They’ll attack and eat any sort of animal that they can either gulp down or tear into manageable bits.

Reproduction and Lifespan

When it comes to reproduction, most moray eels don’t seem to have a breeding season but breed when the circumstances, such as abundant food, are right. Some moray eels migrate a small distance to a spawning site. Once there, the female releases as many as 10,000 eggs with a chemical that attracts males to the area so they can fertilize them. After this, the eels return to their usual home range and take no more care of their offspring.

Moray eel eggs hatch after a few days to a week, after which the larvae (leptocephali) drift in the plankton for several weeks to months. Depending on the species, they can spend two years drifting on the currents until they’re mature enough to hunt and find shelter.

History and Evolution

Several interesting evolutions of the Moray Eel make them one of the more interesting swimmers in our oceans. Their high number of vertebrae makes their bodies long and slender, and they are able to propel themselves through the water quickly. As mentioned, their two sets of jaws are an incredible adaptation that has helped different species with differing diets. Some species have smoother teeth to help break down prey with shells, and some Moray Eels can lay their back jaw’s teeth almost flat to help their food slide through their throats.

Fishing and Cooking

Though some people eat moray eel, this is inadvisable as the eel often is ciguatoxic. Eating a contaminated eel can cause ciguatera fish poisoning, a potentially serious disease.