Ribbon eels are aptly named for their delicate movements, as they swim like a slender ribbon dancing in the water column. Technically, all ribbon eels are moray eels. These colorful species are considered protandrous hermaphrodites, beginning life as a male, and as they mature, they switch sexes to female, developing female sex organs once ready to reproduce. Ribbon eels are long-lived, living up to 20 years in the wild.

Featured image credit: Bernard Dupont

Male Ribbon Eel in Reef
Male Ribbon Eel in Reef

Image credit: Francois Libert


Appearance

Ribbon eels are colorful, slender-bodied animals with all species beginning their lives as black-bodied and a yellow ribbon along the dorsal fin. Dependent upon the life stage, ribbon eels then turn blue and finally yellow. Juveniles are always black. The ribbon eel, one of over 200 species of moray eels, turns blue once reaching 66 to 102 cm. ( 26 to 40 in.). At a maximum length of 130 cm. (4 ft.), the ribbon eel turns yellow. Leaf-like elongations of the anterior nostrils serve as antennae to minute changes in the environment, helping them to hunt and defend themselves.

Blue Phase Ribbon Eel
Blue Phase Ribbon Eel

Credit: Francois Libert


Diet

As a carnivorous eel, this species eats small fish and crustaceans. Ribbon eels are nocturnal, only leaving their small reef crevices under cover of darkness. These eels naturally hold their heads out of their burrows, allowing them to ambush unsuspecting fish. They use their leafy nostrils in a clamped position to attract prey, then catch their items with their strong jaws.

Ribbon Eel Showing Leafy Nostril Protrusions
Ribbon Eel Showing Leafy Nostril Protrusions

Credit: Christian Gloor


Habitat

Ribbon eels are found in the Pacific Ocean and Indonesian waters from East Africa to southern Japan, Australia, and French Polynesia. These eels live in lagoons and coastal reefs, taking shelter in crevices and burrows. They are most often seen with their heads and part of their anterior bodies extended from their hiding places. Living amongst the reefs, the ribbon eel can be found from one to over 200 feet down. Most interesting is that males are known to share space with each other in their burrows and hideouts.

Two Male Ribbon Eels Sharing Reef Burrow
Two Male Ribbon Eels Sharing Reef Burrow

Credit: Richard Ling


Reproduction

When the water is warmest, ribbon eels will come together to mate. Females die soon, typically within one month, after laying leafy-shaped eggs that float within the water column for about eight weeks.

Black-Phased Ribbon Eel
Black-Phased Ribbon Eel

As protandric hermaphrodites, these eels can change their sex as they mature into different life stages. All ribbon eels start life as male and become female when they are sexually mature and ready to mate. If a black/yellow or blue/yellow ribbon eel is spotted, it is sure to be known as male. Once the ribbon eel turns all yellow, we know them to be in the female and final stage of life.

Threats

Though ribbon eels have a conservation status of Least Concerned, the home aquarium trade is their number one threat. Sought after for their beauty, these specimens rarely live beyond a single month in captivity. Natural threats to ribbon eels are larger fish and sea birds.

Facts about the Ribbon Eel

  1. Like other moray eel species, the ribbon eel can be found with its mouth in an open position, closing it over and over. This is not an aggressive behavior but rather a way to circulate water over their gills.
  2. They are unlikely to change their living territory, so they may live in the same spot for many years.
  3. During the larvae stage, the ribbon eel’s body is transparent.
  4. Ribbon eels grow up to four feet long.
  5. The ribbon eel is always born male and black-bodied, then changes color to blue-bodied, then eventually switches sexes to female and an all-yellow body.
  6. Ribbon eels can fit into tiny, narrow crevices along the reefs where they live.
  7. Eggs that are laid by the female float about the ocean for eight weeks before hatching.
  8. Female ribbon eels die within one month of laying eggs.
Yellow Phase Ribbon Eel
Yellow Phase Ribbon Eel


FAQs

Do Ribbon Eels bite humans?

Ribbon eels are not known to bite humans, though they certainly could if cornered. They look aggressive as they open and close their mouths over and over while sticking their heads out of their burrows. This is a way to move water over their gills and is not meant as a threat.

What do Ribbon Eels eat?

Ribbon eels eat small fish and crustaceans, using their nostril protrusions to attract prey, then ambushing them with their strong jaws.

Is the Ribbon Eel a hermaphrodite?

Ribbon eels eat small fish and crustaceans, using their nostril protrusions to attract prey, then ambushing them with their strong jaws.

Why is it called a Ribbon Eel?

Though rarely seen swimming outside of their burrows and crevices, the ribbon eel looks like a dancing ribbon with its tall dorsal fin, while it swims in open water.

Do Ribbon Eels change color?

All ribbon eels are born black with a yellow dorsal fin. As they age out of the juvenile stage, they turn a bright blue, keeping the yellow dorsal fin. Yet again, as they move into the reproductive phase of life and are ready for mating, they turn all yellow.

Synonyms:
Leaf-nosed Moray