Facts You Should Know About Moray Eels

Here are some interesting facts!

The moray eel is a member of the Muraenidae family. Around the world, there are an estimated 200 known species. The fine snake-like body has a long dorsal fin which stretches from head to tail. The dorsal fin actually merges the dorsal, caudal and anal fin into what appears to be a single, unbroken structure. The moray eel has no pelvic or pectoral fins. It attacks its prey through ambush techniques, and is a very quick and agile swimmer. The moray eel spends a lot of time in crevices, inside wrecks and under rocks. They are a much loved photogenic species and are well recognised in the scuba diving community.

1. A posture which is often false interpreted.

A moray eel, at rest will open and shut its mouth constantly. Often this posture may be seen as a threat, but in reality the eel breathes in this manner. Moray eels don’t have any form of gill cover on the side of their heads, no bony gill-cover like fish. Instead, they pump water orally through their mouth, which in turn passes through two round openings behind the head. This constant movement of water allows the moray eel to extract oxygen from the water as it passes through the oral cavity.

2. The moray eel has two sets of jaws.

The construction of the oral jaws of a moray eel looks very prehistoric. The actual jaw of the eel contains rows of teeth which firmly grip the prey. Inside the oesophagus there is a set of concealed pharyngeal jaw. When the moray eel tightly grips the prey, the second set of jaws shoot forward, bite the victim and pull it down the gullet. The teeth of a moray eel point in a backward direction so the prey cannot escape once it has been captured.

3. Sharp and blunt teeth.

Most moray eels have curved, sharp teeth, which enable it to catch and snag fish. However, some species, such as the zebra moray (Gymnomuraena zebra) have blunt teeth compared to other moray eels. Their diet consists of molluscs, sea urchins, clams and crab, which require strong jaws and special teeth. The zebra moray will grind down its prey and the hard shells; its white pearly teeth are very strong but blunt.

4. Giant morays can weigh up to 30 kg in weight.

The giant moray is the largest of the eel family. Measurements of approx. Two meters and thirty kilograms in weight have been recorded. Unrecorded larger sizes have been sighted by divers, but no known records exist. These huge morays are often sighted in the Red Sea, the coast of Africa and the Pacific region towards Indonesia. The giant moray eel is not found in the Mediterranean Sea.

5. Most moray eels are nocturnal.

When the sund drops below the horizon the moray eel will venture out to hunt its prey. They are, in general, a nocturnal mammal which hunt at dusk and in the night. The moray eel has large eyes, but their eye sight is poor, though the sense of smell is excellent. On occasions, a moray eel will team up with a grouper to hunt prey. Small fish between rocks will be hunted by the moray eel, the grouper hovers overhead and waits for the prey to bolt. If the small fish don’t bolt for safety, the moray eel will catch them among the rocks. One predator will get a meal!

6. The moray eel can tie itself in a knot.

If the prey swims down into a narrow crevice where the moray eel cannot go, the eel will try to force the prey out into the open. The eel will tie a loose knot in its tail region, the force the knot along its body down to its head. It hopes, through concentrated impact and force directed into one space it can push its prey out into open territory.

7. A Green Moray (Gymnothrax funerbris) is actually brown.

To ward off predators, the moray eel is able to secrete a layer of mucus over its skin. This mucus gives the eel a greenish colour, but in actual fact the eels colour is brown. The mucus contains toxins which destroy red blood cells and change the appearance of the eel.

8. At least 200 known Species of Moray Eel.

Categorically the moray eel is divided into two categories. One being the true moray eel, the second category are the snake moray eels. The true moray eels are most common with 166 recognised species. The main difference between the two categories is anatomical; the true moray eel has a dorsal fin which begins directly behind the gills, while the snake eels appendage in found only along the tail region.

9. The Moray Eel is not Aggressive.

Under normal circumstances the moray eel will not attack a scuba diver or a swimmer. Their bite is indeed very physical, severe and painful, but the eel will not go out of its way to attack. Albeit if the eel is threatened with a close-up camera or its home is being abused it will defend its territory. The moray eel can be aggressive during the breeding season, but if left alone and treated with respect they will do no harm to humans.

10. Breeding

The moray eel is oviparous like other eel species. The eggs are fertilised outside the womb. Female moray eels lay eggs well-hidden from predators, then they emit an odour to attract male eels. The odour entices the male eel to come and place his sperm in the eggs. After fertilisation, the offspring take 30 to 45 days to hatch. Warm water is considered best for the mating and fertilisation process. The young hatch quicker and take care of themselves, although they are heavily preyed upon by predators.

If you want to learn more about fish identification, why not take the PADI Fish Identification specialty course?

Photo by Janet Bulmer @ www.divesmartgozo.com