Female Ribbon Eel (Rhinomuraena quaesita)

 

This female is still showing some residual blue 'male' colouring.

Photograph by Scott Tuason

The ribbon eel (Rhinomuraena quaesita) is regarded by most as the aristocrat of the moray family. Elegant and unusual, this elusive creature is commonly found on coastal reef margins and in protected lagoons throughout the Indo Pacific region. Unlike its well-built moray cousins, the ribbon eel's gracefully long body is thin and ribbon-like. The other distinguishing feature is its enormously elaborate nostrils that look like membranous leaf-like structures and are used to pick up water vibrations and aid prey capture. These nostrils are the basis for the eel's other common name - the leafy nose moray.

The most amazing thing about the ribbon eel is its ability to undergo drastic colour and gender changes throughout its life. The species is a hermaphrodite, and it is widely accepted that as a juvenile the eel is jet black with a yellow dorsal fin.

This black will fade into a distinctive brilliant turquoise blue with much of the snout and lower jaw becoming yellow. This is the male blue colour phase that has once fooled many ichthyologists into classifying it as a different species, Rhinomuraena amboinensis.

Finally, when it reaches a body length of 85 to 130cm, the eel develops its female sex organs and changes its colour again to a greenish yellow, progressing to entirely golden yellow. This mature female will then mate, lay its eggs and eventually die when its body further fades to a pinkish white colour.

Divers rarely encounter this female yellow form, as it is extremely shy in the wild and known to have a very short life span of a month or less.

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