Coris gaimard (Yellowtail Coris) Breeding Guide

Coris gaimard is a sand-associated Indo-Pacific wrasse that broadcast-spawns pelagic eggs in pairs. It reaches 40 cm and is not reproduced in home aquaria.

Overview

Coris gaimard, the Yellowtail Coris, is a labrid of the central Indian Ocean and western Pacific, ranging from Christmas and Cocos-Keeling Islands east to the Society Islands, north to Japan and Hawaii and south to Australia. FishBase gives a maximum total length of 40 cm, with most fish not exceeding 20 cm. It lives over mixed sand, rubble and coral from 0 to 50 m. Juveniles are bright red with black-margined white spots, while adults develop a green body with blue specks and a bright yellow tail. FishBase classifies it as oviparous with distinct pairing during breeding.

Sexing

As a labrid, the species follows the family's protogynous pattern, in which fish mature as females and the largest transition to terminal-phase males according to social hierarchy. The dramatic colour change from juvenile to adult is unrelated to functional sex, so external sexing for pairing is unreliable at the point of purchase.

Conditioning

FishBase describes a diet of molluscs, crabs and hermit crabs, with occasional tunicates and forams. Any conditioning effort would therefore rely on varied meaty invertebrate foods in a large, deep-sand system. There is no published conditioning protocol that has led to spawning in captivity.

Breeding Setup

No aquarium breeding setup exists for C. gaimard. The fish requires a substantial sand bed to dive into for shelter and sleep, plus space appropriate to a wrasse that can approach 40 cm. Wild reproduction occurs over open reef and sand flats where pairs ascend to release gametes.

Spawning Behavior & Trigger

Labrids broadcast-spawn planktonic eggs that are dispersed by currents, with no parental care. FishBase records distinct pairing during breeding. The triggers are reef-scale environmental cues, not parameters that can be set in a tank, so spontaneous spawning is not expected in captivity.

Egg & Fry Care

Eggs are pelagic and the hatched larvae are planktonic, drifting in open water before settling. The tiny first-feeding larval stages of broadcast-spawning wrasses have no practical home-aquarium equivalent, which is the core reason the species is not captive-bred.

Common Challenges

Pelagic broadcast spawning, planktonic larval rearing, the requirement for a deep sand bed, the large adult size and the protogynous social structure together make purposeful breeding impractical. C. gaimard should be treated as a wild-collected display fish rather than a breeding subject.