Apogon margaritophorus Breeding Guide

Apogon margaritophorus is a small paternal-mouthbrooding cardinalfish that pairs distinctly during courtship; the male incubates the egg ball in his mouth. This guide covers sexing, conditioning, spawning and fry care.

Overview

Apogon margaritophorus (treated by FishBase as Ostorhinchus margaritophorus), the pearly-lined or red-striped cardinalfish, is a small member of the family Apogonidae reaching about 6.5 cm total length. It occurs in the western central Pacific from the Indo-Malay Archipelago to the Solomon Islands, on shallow coral reefs around lagoons and sheltered bays at depths of 1 to 5 m, often in small groups sheltering near long-spined urchins or large anemones. Like other cardinalfishes it is a paternal mouthbrooder.

Sexing

As in other cardinalfishes, mature males have a larger jaw and longer head to hold the egg mass during incubation, the most reliable distinguishing trait. Outside the breeding period the sexes are otherwise similar, so the male is usually identified when seen brooding.

Conditioning

This small carnivore conditions on a varied diet of small meaty foods reflecting its natural prey. Keeping a small group encourages a compatible pair to form. A mature reef offering urchin or anemone cover, as used in the wild, helps the fish settle and reach breeding condition.

Spawning Behavior & Trigger

FishBase records distinct pairing during courtship and spawning for this species. After pairing, the female releases eggs that the male takes into his mouth and fertilises, forming a cohesive egg mass that he then broods.

Egg & Fry Care

The male incubates the egg ball orally and does not feed while brooding, a pattern shared across the family. On release the young enter a pelagic larval phase and require small live first foods, so grow-out is best done in a dedicated larval system rather than the display tank.

Common Challenges

Keeping the brooding male undisturbed so he retains the clutch, and feeding the small pelagic larvae through their first-food stage, are the principal challenges. As with other small cardinalfishes, larval feeding rather than spawning is the limiting step.