Moray eels tend to have an inequitable reputation as fierce, merciless serpents just waiting to launch a bloody attack on anything that wanders too close. Knowing morays as I do, though, I’d say this reputation is about as justified as saying the same about all dogs – yes, some dogs may bite if you enter their territory uninvited or if you provoke them but, generally, if you act with quiet respect, you’ll be tolerated and might even be welcomed with a wagging tail.
In this regard, moray eels are much like man’s best friend … only long, slimy and with gills.
Ask dive legends Valerie and Ron Taylor, an adventurous couple who played a pioneering role in placing sharks on our television screens. Among the many friendships that Valerie forged under the sea, she famously developed a close bond with Honey, a huge honeycomb moray living in Indonesia’s Banda Sea, as well as with Harry and Fang, giant morays from Heron Island on the Great Barrier Reef. Video footage of her interactions with these slippery friends goes a long way to debunking the vicious sea-serpent myths.
While morays are actually fish, they’re very un-fishlike. They totally lack scales and the usual set of pectoral and pelvic fins seen in their more typical fishy cousins. Instead, their dorsal fin stretches from behind the head and melds seamlessly with the caudal and anal fin, coming to an end under the belly.
Their long and sinuous forms are perfectly adapted to a life of weaving in and out of winding holes in the reef, or sliding through the sand on the sea floor. By using rhythmic sideways undulations of the body, morays move with striking grace, speed and efficiency in their daily search for prey and shelter.
Their skin produces a large amount of mucus, which aids in fluid movement through their environment – in some species, this mucus even contains a protective toxin.
But the most unusual of their adaptations is their pharyngeal jaw, which is essentially a second set of teeth (think Alien, the movie). At rest, it lies back in the throat, but when the moray grabs something using its needle-like front teeth, this smaller, secondary jaw shoots forward to secure the wriggling victim and transport it back into the throat … and this is why we never harass or hand-feed these animals!
Of the 200 or so species of moray eels in the family Muraenidae, the largest, by body mass, is the giant moray (Gymnothorax javanicus), an animal that reaches 3m in length and weighs almost as much as an average nine-year-old boy – around 30kg. It is a common and widespread species, occurring throughout reefs in the Indo-Pacific region. During daylight hours, divers frequently encounter this denizen peering from crevices in the reef, with only their huge heads, staring eyes and massive gaping mouths visible. But as twilight falls and the reef changes guard, the morays go hunting for crabs, octopus, lobsters and sleeping fish – and only then can the true size and girth of the giant moray be appreciated.
I’ll be honest – when I’m buried in my camera’s viewfinder, shooting nocturnal images of diminutive decorator crabs and nudibranchs, being surprised by a passing 3m moray does send a pulse of adrenalin coursing through my veins! But then I calm myself down by singing a line from a parody of Dean Martin’s song That’s Amore: “If it’s slimy and green and its big jaws look mean, it’s a moray!”