Just about everyone remembers the first time he or she spotted a moray eel while diving; who could forget that first look at the wide, gaping mouth, seemingly menacing eyes, and aggressive looking posture? Only after a little study time do we find out that Moray eels are not out to get us; in fact, they would rather stay at home, watching divers pass from the comfort of their dens. Let’s take a closer look at these fascinating animals.
That’s A Moray: The Basics
The huge Muraenidae family is made up of approximately 200 different moray eel species. While most species are found in salt water environments, some do live in brackish water, and others can even live in fresh water. Found in both tropical and temperate seas, moray eels are commonly found in a variety of reef and wreck environments and can live in depths ranging from just a few feet of water to several hundred meters.
Among the many species, the smallest is Snyder’s Moray, which can be found in most Pacific Ocean reef environments. It takes a sharp eye to spot one of these little morays; they grow to be just about 4.5 inches long and tend to be reddish brown with dark and light spots designed to help them blend into the background. The largest moray eels by mass are the Giant Moray, but by length, the Slender Giant Moray is the larger of the two. Giant Moray Eels can be as long as ten feet and weigh more than seventy pounds. Slender Giant Moray Eels can be more than twelve feet long, but weigh less; preferring muddy environments; the slender giants tend to be grey in color while Giant Morays have a leopard-like spotted pattern and are more widely distributed, being found all throughout the Indo-Pacific region, Red Sea, and Africa.
Despite the fact that all moray eels have similar characteristics, with long, slender bodies, large teeth, and forward-thrusting jaws, their colors vary greatly. Commonly encountered colors include brown, green, black, yellow, blue, and even an off-white color. Often, morays are speckled or striped, with some notable species including the Snowflake moray, which is black and white, and the Chainlink moray, which is black with a bright yellow pattern on its skin. Blue Ribbon Moray Eels are some of the most colorful; the males are bright electric blue, females are yellow, and juveniles are black.
Diving With Moray Eels
Moray eels are part of a normal, healthy reef ecosystem; their behaviors may seem threatening at first, as they have a menacing, gaping appearance. The reason, though, that their mouths are almost always wide open, is that they have small gills, and must open and close their mouths in order to breathe properly. Moray eels will attack if threatened, and while some divers insist on feeding them, some unlucky people have had their fingers bitten off and swallowed, as the fish have no idea where the treat ends and your fingers begin.
Never feed a moray eel, even if someone tells you it is safe to do so. The fact is, the moray’s jaws are not capable of opening once they have grasped an object, until that object is swallowed or the moray is pried off. Moray eel feeding is prohibited in many areas, particularly on Australia’s Great Barrier Reef. While their bites are not normally venomous, the severity of a wound caused by a moray bite is great enough that even those divers who have escaped with fingers intact have later required serious medical intervention, including amputation.
While morays are most often seen peering out from the shelter of the cracks and grottoes where they like to hide, you may be lucky enough to see free swimming moray eels from time to time, particularly on night dives when they tend to emerge to hunt. If so, you’ll see how muscular their bodies are. A fortunate few may even get to see morays visiting a cleaning station, where cleaner wrasse and shrimp gently pluck parasites from their skin.
In some cases, shrimp will take up residence with a moray eel, plucking food particles from the eel’s mouth as it relaxes inside its den. While this is a form of commensalism which is seen fairly often, another amazing phenomenon occurs with morays, in which they form hunting partnerships with groupers from time to time. This is rarely seen, but if you do encounter a moray and grouper hunting together, it will begin with the grouper shaking its head to get the moray’s attention, after which the moray will assist the grouper by chasing prey out of cracks too small for the fish to enter. This is the only inter-species hunting behavior known to exist between fish.
Moray mating behavior is incredible, and takes place when water temperatures are at their warmest. The morays first posture at one another by gaping widely, then join, intertwining their bodies before releasing clouds of sperm and egg into open water. At times, multiple eels will intertwine with one another, and interestingly, some are hermaphroditic, being capable of pairing with other morays of either gender. Once the larvae emerge from their eggs, they float free for about 8 months before finally becoming elvers, and swimming down to inhabit reef environments. Depending on species, morays life spans vary from 6 to 36 years or so.
Having very few natural predators other than bigger morays, large barracudas and groupers, and people, most moray eel species are stable; the biggest threat to their survival is the destruction of reef habitat. While some species are fished, they are not generally safe to eat; they tend to contain the toxin Ciguatera, and people have died after consuming moray eel. One notable victim was King Henry the First of England, who died shortly after feasting on a surfeit of morays in Normandy in 1135.
Some of the best places to dive with moray eels include the Galapagos and Cocos Islands, the reefs of Australia and Fiji, the Lembeh Strait and other Indonesian locations, the Maldives, Thailand, Malaysia, and the Red Sea, where some of the more colorful species are found and reefs are at their best.