Giant Moray Eel

The giant moray (Gymnothorax javanicus) is a species of moray eel and a species of marine fish in the family Muraenidae. In terms of body mass, it is the largest moray eel. The body type of this specific eel is similar to that of an electric eel. (the slender giant moray is longer).

It is a large eel, reaching up to 3 m (9.8 ft) in length and 30 kg (66 lb) in weight. Its serpent-shaped body has a brownish background color. While juveniles are tan in color with large black spots, adults have black specks that grade into leopard-like spots behind the head and a black area surrounding the gill opening.

Giant moray is widespread in the Indo-Pacific region, being found from eastern coast of Africa, Red Sea included, until the Pitcairn group, Hawaiian islands and also Polynesia. North to south Japan and south to New Caledonia, Fiji and the Austral Islands.

Studies as well as personal reports confirm that the bite of a moray eel can be much more painful than the bite of other predatory fishes of similar size. This hardly can be explained by a “pulling back effect,” which means that one automatically pulls back a bitten limb and thus increases the wound by driving the moray eel’s teeth through the flesh forcefully.

It was suggested that bleeding and pain are related to a toxin in the slime coat of the skin and the mucous of the mouth. And truly, the mucous of moray eels was analyzed, and not just one, but several toxic substances were found. One of these substances is hemagglutinin. This is a glycoprotein that causes red blood cells to clump. Another toxin found in the mucous coat of moray eel was shown to be haemolytic, meaning the toxin destroys red blood cells. Since these toxins are related to glands in the skin of the eel, they are also called crinotoxins.

Moray eels, like many other predatory fishes, carry the possibility of storing specific toxins in their flesh/organs. The two most prominent substances are ciguatoxin and maitotoxin. These toxins cannot be destroyed by heating the fish to 75°C. They can lead to a type of food poisoning known as ciguatera. It’s good that these substances are not transferred by bites.