Ambon Chromis Breeding Guide

Breeding Chromis amboinensis: a Western Pacific demersal nest spawner where the male clears and guards a substrate nest, the female lays adhesive eggs, and pelagic larvae disperse after hatching.

Overview

Chromis amboinensis (recorded by FishBase as Pycnochromis amboinensis) ranges in the Western Pacific from the eastern Indian Ocean to Samoa, Tonga and the Marshall Islands, reaching about 10 cm. Adults inhabit caves on steep outer reef slopes, often below 24 m, while juveniles occupy shallow branching corals. FishBase records it as oviparous with distinct pairing during breeding, demersal eggs adhering to the substrate, and male guarding and aeration. IUCN status is Least Concern.

Sexing

External sexual differences are slight outside the breeding period, so reproductive role is the practical guide. The male establishes and tends a substrate nest while the female enters to lay. Because this species congregates in groups, keeping several together is the most reliable way to obtain a compatible pair.

Conditioning

A group held in stable reef water and fed several small daily meals reaches condition. Regular feeding of fine planktonic and meaty foods supports egg production and matches the planktivorous habit of this aggregating reef-slope chromis recorded on FishBase.

Breeding Setup

Following the pomacentrid pattern the male clears a patch of hard substrate near reef structure to form a nest, so the system should provide exposed firm rock with nearby shelter within a defensible territory. A spacious tank with deeper rockwork suits a species that naturally favours steep slopes and caves.

Spawning Behavior & Trigger

Damselfish court with ritualised displays of rapid movement, chasing and fin extension near the nest. The female lays a layer of adhesive eggs on the cleared substrate, and the male fertilises them externally. FishBase records distinct pairing during breeding for this species.

Egg & Fry Care

The demersal eggs adhere to the substrate and are guarded and aerated by the male. Across Pomacentridae incubation takes about two to seven days, releasing larvae of roughly 2 to 4 mm into a pelagic stage of about a week to more than a month, feeding on very small live plankton such as cultured copepods.

Common Challenges

The pelagic larval phase is the decisive obstacle: the minute larvae require a continuous supply of dense live plankton beyond what a typical display tank provides. With no documented species-specific rearing protocol, captive spawning of Ambon Chromis usually ends at the planktonic larval stage.