Blue Ribbon Eel (Rhinomuraena quaesita) Breeding Guide

Why the blue ribbon eel Rhinomuraena quaesita is not bred at home: a protandric hermaphrodite that dies soon after spawning and produces an unrearable leptocephalus larva.

Overview

Rhinomuraena quaesita is a moray of the Indo-Pacific, recorded from East Africa to southern Japan, Australia and French Polynesia at depths of 1-57 m. It is a protandric hermaphrodite, changing from jet-black juveniles to blue males and finally to yellow females, and is notoriously difficult to keep, with most captive specimens dying within a year. It is not bred in home aquariums.

Sex Change and Reproduction

This species is generally considered a protandric hermaphrodite, transforming from male to female. Wikipedia describes how a male develops reproductive organs, lays eggs and then dies within roughly one month of completing this transition; blue males measure about 65-94 cm while yellow females reach up to 130 cm. This compressed, terminal reproductive phase is unusual among moray eels.

The Leptocephalus Larva

Larval ribbon eels are described as a large, greenish leptocephalus — the flattened, transparent, leaf-like larval form typical of eels. Leptocephalus larvae have a prolonged planktonic life and highly specialised feeding requirements, and rearing them is not achievable in a home aquarium, which is the central reason the species is not propagated outside rare public-aquarium events.

Why It Is Not Home-Bred

Spawning has occurred at some European and North American public aquariums, but most captive specimens die within one year after refusing all food, so simply maintaining a healthy long-term individual is already exceptional. Combined with the protandric, short terminal reproductive window and the unrearable leptocephalus larva, this places breeding entirely beyond the home aquarist.