There are approximately 200 species of Moray eels (Muraenidae), who are virtually exclusively marine dwellers. However several species are seen in brackish water, with also a few living in fresh water.
Moray Eels range from 11.5cm to 4m depending on the species. We are lucky enough to have the largest of these, namely, Giant Morays (Gymnothorax Javanicus) in plentiful supply on all our dive sites. Giant Morays really can get huge and weight up to 30kg. To see them swimming free is pretty spectacular.
Moray Eel facts
Moray Eel Bad Reputation
The Moray Eels aggressive reputation, really comes from the fact they continuously open and close their mouths in a gaping fashion. This behaviour has nothing to do with aggression but merely to maintain a flow of water over their relatively small gills and facilitate respiration.
Male, Female or Both?
Scientific studies have shown hermaproditism in Moray Eels. Some are male but later becoming female and others are both male and female and can reproduce with either sex. They take 3 years to reach sexual maturity.
Mating begins when water temperatures reach their highest and they begin sexual posturing in the form of gaping widely. The Morays will wrap each others’ long bodies together, either as a couple or two males and a female. They can simultaneously release sperm and eggs in the act of fertilisation, which signals the end of their relationship. Or, are also know for the females to release eggs and the males later fertilise them.
Moray Eels are totally self sufficient when they hatch from eggs after 30-45 day gestation period. They initially take the form of larvae in the open ocean but after about 8 months, swim onto the reef to begin life as a Moray Eel.
Toxic Moray Eel
Morays Eels are toxic as a result of toxic dinoflagellate which is accumulated up through the food chain, of which moray eels are top. Although they are fished, they are not eaten for this reason. This fact was apparently the cause of death for King Henry I of England, who expired shortly after feasting on a moray eel. In this respect, Moray Eels are not regarded as endangered.