Synchiropus moyeri Breeding Guide

Moyer's dragonet Synchiropus moyeri is a western-Pacific copepod feeder living in harems with a dominant male, and like other dragonets it spawns by a dusk pair-ascent releasing pelagic eggs.

Overview

Synchiropus moyeri, Moyer's dragonet, is a reef-associated dragonet of the family Callionymidae reaching about 7.5 cm total length. It is widespread in the western Pacific, where it replaces the closely related Synchiropus stellatus of the Indian Ocean, and inhabits coastal reef slopes over rubble and sand near large coral formations at depths of 3 to 30 m. It typically occurs in small loose groups in which one large male dominates a section of reef.

Sexing

The species is sexually dimorphic in the manner typical of dragonets, with the dominant male larger and more developed than the females of his group. Because small groups occur with a single adult male, the largest, most fin-developed individual is generally the male.

Conditioning

As a benthic-invertebrate feeder, the species depends on live copepods to reach and hold breeding condition. A mature reef or attached refugium with self-renewing pod populations is the practical way to condition a male with one or more females.

Spawning Behavior & Trigger

Dragonets spawn in the late afternoon just before sunset. After a courtship display in which both fish fan their pectoral and caudal fins and the male flares his dorsal fins, a male and female pair ascend roughly 0.7 to 1.2 m up the water column, swimming semicircularly with the pectoral fins, and release eggs and milt near the top of the rise. Dominant males are polygynous and may spawn with several females in a single evening.

Egg & Fry Care

The eggs are buoyant and pelagic, drifting freely with the plankton, and there is no parental care. In a closed system eggs must be collected as they rise and the planktonic larvae fed extremely small first foods, which is why rearing has been achieved only in specialist conditions.

Common Challenges

Capturing floating eggs before filtration removes them and feeding the minute larvae are the principal obstacles, compounded by the need to sustain dense copepod populations for both adults and fry. As a result reproduction is rarely documented beyond egg release.