Genicanthus melanospilos (Spot-Breasted Angel) Breeding Guide
Genicanthus melanospilos is a reef-safe swallowtail angel with striking sexual dichromatism that pair-spawns pelagic eggs. Larval rearing is a specialist task; home breeding is impractical.
Overview
Genicanthus melanospilos is a swallowtail angelfish of the western Pacific, from Indonesia to Fiji, north to the Ryukyu Islands and south to New Caledonia and the Rowley Shoals. It reaches about 18 cm at depths of roughly 20 to 45 m on steep outer reef slopes and drop-offs, feeding on plankton in midwater. The genus is reef-safe and is considered the most breedable among angelfish.
Sexing
The species shows striking sexual dichromatism typical of the genus: males are yellowish with vertical body bars, while females carry a thick dark dorsal stripe. This makes the sexes easy to distinguish. As a protogynous hermaphrodite, the dominant female will change sex to male if the male is lost from the group.
Spawning Behavior & Trigger
In the wild it is generally seen in pairs or in loose groups of females dominated by a single male on outer reef slopes. Swallowtail angels are pair-spawners: courtship intensifies toward dusk, when a female ascends into the water column with the male and releases buoyant pelagic eggs at the peak of the rise.
Egg & Fry Care
Genicanthus eggs are extremely small and pelagic, hatching into minute prolarvae. Standard rotifers exceed their first-feeding gape, so rearing in related species has depended on cultured copepods and similarly tiny live prey. There is no parental care, and larval rearing rather than spawning is the limiting step.
Common Challenges
- Pelagic eggs disperse on release and cannot be collected from a display.
- Prolarvae are too small for rotifers and need cultured copepods.
- A pair requires a large reef system to settle and spawn.
- Captive rearing is confined to commercial or research facilities.