The Enigmatic moray eel (Gymnothorax enigmaticus) is also known as the Banded Moray Eel. They are not common in Tanzanian waters and one occasionally sees them out at night hunting for prey on the shallow offshore reefs. They were described by McKosker & Randall in 1982.
The Enigmatic moray eel is one of the smaller species, growing up to 58 cm in length. grows up to 140 cm in length. The body color is an off white with brown mottling and there are a series of indistinct black bars on the body that vary from specimen to specimen. The nostrils on some specimens are brown with yellow ends.
The mouth has sharp backward curving teeth for grabbing prey. They do not have pectoral or pelvic fins and the dorsal fin runs the length of the body.
ENIGMATIC MORAY EEL IN THE WILD
Enigmatic moray eel are nocturnal feeders and spend the days hiding in crevices in the rocks. One seldom if ever sees them out during the day. At night they are sometimes seen out in the open hunting, but once one puts lights on them they quickly retreat into a crevice.
Moray eels have proportionately small circular gills, located on posterior of the mouth and the moray is constantly opening and closing its mouth to facilitate sufficient water flow over its gills. In general the opening and closing of the mouth is not threatening behavior but one should not approach too closely. They will bite if threatened.
Some researchers speculate that moray eels contain toxins in their mouths and are poisonous. From many years of catching crayfish on the Kwa Zulu Natal coast I have never had a bite go sceptic. After every bite I have soaked the bite area in hot water as hot as I could take it. Enigmatic moray eel secrete mucus over their scaleless skin, which in some species contains toxins. They have a thick skin and a large number of cells that secrete mucus.
The Enigmatic moray eel is widespread across the Indo-Pacific area, being found from the East Coast of Africa northwards, Gulf of Aden included, across to the Tuamotu Islands, north to southern Japan and south to Australia. They are found in rocky reefs, coral reefs and occasionally in lagoons provided there is shelter. The adults are usually found from depths of 8 to 15 meters and the juveniles are found close to shore.
The Enigmatic moray eel is carnivorous, and does most of its hunting at night. They feed mainly on small fish and crustaceans. Moray eels have a second set of jaws in their throat called pharyngeal jaws, which also have teeth. When feeding, morays latch onto the prey with their outer jaws. They then push their pharyngeal jaws which are set back in the pharanx, forward into the mouth.
They then grasp the prey and pull it into the throat and stomach. Moray eels are the only fish that use pharyngeal jaws to capture prey. Their main hunting tool is their excellent sense of smell which makes up for their poor eyesight. This means that weakened or dead creatures are the moray eel’s favored food.
Studies have shown hermaphroditism in morays, some being sequential and others synchronous which can reproduce with either sex. Courtship usually occurs when water temperatures are high. After posturing to each other they wrap their bodies around each other and simultaneously release sperm and eggs. Once they hatch the larvae float in the ocean for around 8 months before becoming elvers and eventually a Enigmatic moray eel.
Ciguatoxin, the main toxin of ciguatera, is produced by a toxic dinoflagellate and accumulated up through the food chain, of which moray eels are top, making them potentially dangerous for humans to eat. Moray Eels are fished and do take bait. There is documented evidence of Ciguatoxin poisoning from some species of moray eels and because of this they should not be eaten.
Once caught on a line they are extremely troublesome to deal with. They wrap around the line and secrete a large amount of mucus. Unless the line is changed, much as with the mucus from puffer fish, no other fish will bite on the line. It is not uncommon for a caught moray eel to actually bite its self while it is busy wrapping around the line.