Imagine that you’re diving a fantastic reef somewhere in the South Pacific, and suddenly, a bright blue snakelike creature passes a short distance away. You check your dive computer, wondering whether narcosis is setting in, and you pinch yourself, too. What was it? You might have seen one of the most beautiful eels in the world – the ribbon eel. Let’s take a closer look into the lives of these magnificent creatures.
Ribbon Eel Basics
Sometimes called Bernis Eels, and often referred to as Black Ribbon Eels or Blue Ribbon Eels, these saltwater eels are members of the Moray eel family, and are the only member of the Rhinomuraena order. Once, black and blue ribbon eels were thought to be different creatures altogether, but recently they have been categorized as belonging to the same species.
Native to the Pacific and Indian oceans, these elegant eels are recognized by their long, thin, ribbonlike bodies and their peaked dorsal fins. In addition, these animals have large nostrils that give them an almost alien appearance; these nostrils have large leaf-like flaps affixed to them, and researchers have determined that the eels use them to feel vibrations in the water. Like other morays, they are normally observed with mouths gaping wide open in what appears to be a display of aggression; in reality, they are simply breathing.
Juvenile ribbon eels and some young adults are jet black in color, with contrasting yellow dorsal fins. Adult males are a brilliant cerulean blue color with the same yellow dorsal fins as are displayed by juveniles. Females, on the other hand, are not blue at all. Instead, they are yellow with white fin margins and a distinct black anal fin. While juveniles have black faces, adults have yellow snouts and jaws. The inner portions of their mouths are also bright yellow.
These eels grow to be as long as 48 inches, and can live for up to twenty years. They are the only moray eel species and one of the only marine species that is protrandric, meaning that males can transform themselves to females; usually, sequential hermaphroditism works the other way around, with females transforming themselves to males when necessary.
Diving With Ribbon Eels
Now that you know what you’re looking at, you are in for a treat. These eels are absolutely fascinating to observe, particularly as they lie in wait before pouncing on prey animals, such as shrimp and fish. The eels will often bury their bodies in the sand or hide in cracks and crevices to wait for the opportune moment to strike, and as a result you may or may not see these eels swimming free. Often, they will blend right into the reef, as they tend to bury most of their bodies so that only their heads and necks protrude; watch for a slight swaying motion and a flash of bright yellow, and you’ll be able to zero in on the animals. Keep an eye out for them at depths between one and sixty meters, anywhere in the Indo-Pacific region.
While ribbon eels are not aggressive, and while they will normally retreat if frightened, use caution and don’t get too close, as they can sometimes bite. With the right camera equipment and a careful approach, you can get some outstanding shots, and come away with evidence that you really did see this amazing creature and weren’t suffering narcosis.