Muraenidae, most commonly known as Moray Eels, are a family of cosmopolitan eels and therefore reside in locations all over the world in tropical and temperate seas. There are around 200 species of moray eels, with the most common species spotted around Koh Tao being the white eye moray eel, undulated moray eel, albino moray eel and green moray.
Recreational divers can find these animalia in depths up to 40m around Koh Tao’s dive sites. However if we are getting technical, they can be seen at deeper depths of up to around 100m. Want something to put a smile on your face whilst diving? These happy chaps will definitely smile for the Camera.
Eels have a serpentine appearance with generally a patterned body. They have a dorsal fin which extends from just behind the head along the back and joins impeccably with the caudal and anal fins. Their eyes are rather small; morays rely on their highly developed sense of smell, lying in wait to ambush prey.
This is why they are most commonly spotted relaxing in the crevices of pinnacles at numerous dive sites around Koh Tao including Twins, White Rock, Southwest Pinnacle and Chumphon Pinnacle. I recently spotted a baby Undulated Moray, about 10cm long, at Southwest just inside a small crevice in the pinnacle.
Moray eels’ heads are too narrow to create the low pressure most fish use to swallow prey.
So how do they dine? Their jaws are wide, framing a protruding snout. Most possess large teeth used to tear flesh or grasp slippery prey. Furthermore, they have a second set of jaws in their throat called pharyngeal jaws, which also possess teeth.
How cool is that; two sets of jaws? But how do they utilize both? Morays eels launch these jaws into the mouth, where they clench prey and pull it into their throat for delicious dining. Moray eels are so unique that they are the only animals that use pharyngeal jaws to actively capture and restrain prey.
So What Tastes Delicious To These Incredible Sea Creatures?
Morays are carnivorous and feed primarily on smaller fish, octopuses, squid, cuttlefish, and crustaceans. They hunt mainly at night, sometimes waiting in their crevice until prey is close enough for them to launch; using their incredible sense of smell which makes up for their poor eye sight, Groupers, barracudas and sea snakes are among their few predators.
Scientific studies have shown hermaproditism in morays, some being sequential (they are male, later becoming female) and others are synchronous (having both functional testes and ovaries at the same time) and can reproduce with either sex.
Mating among morays begins when water temperatures reach their highest, in which they will wrap their slender bodies together.
Once fertilization has been reached this signifies the end of their relationship. Once hatched the eggs take the form of larvae, which float in the open ocean for around 8months looking like thin-leaf shaped objects. After this, they swim down to begin life on the reef and eventually develop into a moray eel. Eels can live between 6 and 36 years depending on the species in a natural life cycle.
People generally think of eels as vicious, electrocuting or ill-tempered animals, most likely due to Hollywood movies. Well, do not believe this misconception. They are in fact incredibly social animals, especially around Koh Tao! They love posing for a good photo in their crevice! Ever heard the saying fight or flight? Eels are most definitely the first on the plane out of an uncomfortable or scary situation!
Diving With Eels
These guys are the masters of disguise. Or so they think! They may have this secretive style behavior by sitting in crevices but we always spot them. White eyed morays are the most sociable and the easiest to spot!
Recently an albino moray (the rarest around here) has been spotted swimming at Junkyard Reef, our artificial dive site. Also I personally found a large undulated eel last week hiding in a crevice at popular dive site white rock around 14m.
Sail Rock is a popular site to see a large green eel, which we are currently diving every Tuesday!
Would you like the chance to take a selfie with an eel?
If you are interested in seeing these during your dive, you can ask our team at Crystal and they would be happy to advise you on suitable dive sites, and locations.
Author: Keri Gray (PADI MSDT #360928)