What is a Ribbon Eel?

The ribbon eel, also known as the Bernis eel or Rhinomuraena quaesita, is a species of moray eel native to the Pacific and Indian oceans. Its slender body and broad dorsal fin give it the flat, ribbon-like appearance from which it gets its name, and an adult ribbon eel will grow to lengths of more than 3 feet (about 100 cm). Ribbon eels are perhaps most recognizable by their flared, fan-shaped nostrils.

In the wild, a ribbon eel can live for 20 years or more. Over the course of its life, the ribbon eel will change coloration and even gender. Until the eel reaches adulthood, it is black with a bright yellow dorsal fin. As the eel begins to mature, it becomes male, and the black body turns blue. When the eel’s body turns yellow with a black fin, it has reached its female stage.

Another unusual feature of the ribbon eel is the placement of its organs. The kidneys and most of the reproductive organs are behind the eel’s anus. No other vertebrate has organs located in this manner.

Ribbon eels appear to be quite aggressive and might even seem to be angry. Its mouth is constantly open, seemingly on the prowl and ready to strike. In fact, these eels keep their mouths open in order to breathe, not to hunt. In the wild, ribbon eels prefer to conceal themselves in rocks or under sand. To feed, they prefer to strike small fish that stray too close.

Aquarium owners and fish enthusiasts can purchase ribbon eels from pet shops, and their bright colors makes them an attractive addition, but they are notoriously difficult to keep. Even with a good supply of feeder fish, the ribbon eel usually will starve in captivity. Most often, the eel simply will refuse to eat and will die within a month or so. The ribbon eel generally is not recommended for captivity.

For those determined to make the attempt to keep a ribbon eel in captivity, there are some steps that can improve the eel’s chances. Providing concealment, three inches of sand at the bottom of the tank, a pile of rocks or even an artificial cave can help the eel feel more secure and make it more likely to eat. A good supply of feeder fish such as guppies or mollies will be needed, and a smaller tank will help to keep the food close to the eel. Other predatory fish should not be housed with the eel, because they are likely to go after the feeder fish before the eel is ready.

A Ribbon Eel, also known as Rhinomuraena quaesita, is a species of saltwater eel found in the Indo-Pacific oceans. They are typically seen in lagoons and reefs, preferring sandy burrows or crevices. Divers often spot them with just their heads protruding, as they tend to stay within their shelters during the day.

Ribbon Eels are easily identifiable by their elongated, ribbon-like bodies and high dorsal fins. Juveniles and males are usually black with a yellow dorsal fin, while mature males turn a bright blue with a yellow dorsal fin. Females are entirely yellow. Their distinctive, protruding nostrils add to their unique appearance.

Ribbon Eels are carnivorous, primarily feeding on small fish and crustaceans. They use their acute sense of smell to detect prey, which they then snatch using their swift, sudden movements. Their slender bodies allow them to navigate through complex reef structures to hunt effectively.

Ribbon Eels are generally solitary, except during mating. They are territorial and can be aggressive towards other eels. They communicate through body language and can be seen opening their mouths wide as a sign of dominance or defense when approached by other marine life or divers.

Ribbon Eels have a fascinating life cycle that includes sequential hermaphroditism. They start life as males, and some later transform into females for reproduction. This sex change is accompanied by a color shift. Females lay eggs, which hatch into larvae and drift with plankton before settling to the ocean floor to mature.

While the Ribbon Eel is not currently listed as endangered, its population faces threats from habitat destruction, pollution, and overfishing. Conservation efforts are important to ensure the sustainability of their habitats and to monitor their population status, as they are a vital part of the marine ecosystem's biodiversity.