Moray Eel

Picture credit : Simon Dowling

Moray eel or Muraenidae are generally the largest type of eel. There are 200 different species of moray eel found in fresh, marine and brackish waters. Moray eels prefer warmer water and they can be often found in the shallow water and near the coral reefs. Although moray eels are commercially fished, they are not endangered.

Mating season happens every time water temperature and food sources reach the optimal level. Male and female wrap their bodies together for couple of hours. During this time, female can release up to 10 000 of eggs that will be fertilized by the male’s sperm. Fertilized eggs will develop into larva which swims as a part of the plankton (up to year) until it becomes large enough to come back to the bottom of the sea, where it will start its life as a fully formed moray eel.

The size of an adult Moray eel depends on the species. It ranges in length from 6 inches to 15 feet, with an average weight of around 30 pounds. The Moray eel has a long and slender body which resembles to snake, but they do not belong to the group of reptiles – they are true fish.

Like all other fish, moray eels breathe using the gills. They are located behind the head, in the form of the two circular openings. Moray eel keeps its mouth open because it needs to provide constant circulation of the water toward the gills.

Moray eels spends most of their time hidden in the caves and rock crevices on the bottom of the sea. They attacks like an ambush predator that is waiting for the perfect prey to appear. They are not fussy eaters and like to eat fish, octopuses, squid, cuttlefish, crabs, mollusks…

When attacking, they grab a prey using the element of surprise and wrap its body around it until it becomes flattened enough to be swallowed. Another option is to tear apart the victim and eat it one bite after another. Unlike other eels, the moray eel has two sets of sharp teeth. The first set is located in the jaw and other in the throat. Teeth located in the throat are used for breaking up of the food and for facilitated digestion. The teeth are pointed backwards, preventing the slippery prey escaping.

They are know to participate in Cooperative Hunting, and we often see this on Koh Tao. Coral Groupers team up with Moray Eels to increase their hunting chances. The eel’s ability to enter narrow areas and flush out prey with the grouper hanging nearby makes them a dangerous combination for prey. This interspecies teamwork is the only known instance among fish.

Moray eels produce slippery substance, acting as protective mucus, which covers their body. Mucus of some species contains toxins.

Moray eels have large eyes, but does not see well. It has a good sense of smell, which helps it locate the prey.

More fun facts can be found on our Ocean Facts page… check it out and learn about the ocean!