Behn's Damselfish (Neoglyphidodon nigroris) Breeding Guide

Neoglyphidodon nigroris is an oviparous Indo-West Pacific damselfish that lays demersal eggs on the substrate, guarded and aerated by the male. Pelagic larvae make home rearing difficult.

Overview

Neoglyphidodon nigroris is an Indo-West Pacific damselfish ranging from the Andaman Sea through the Malay Archipelago to northern Australia and the western Pacific islands, reaching about 13 cm total length. Juveniles are bright yellow with black stripes while adults darken. FishBase records it as oviparous with distinct pairing during breeding, following the family's demersal-spawning, male-guarded pattern. IUCN assessed it as Least Concern in 2021.

Sexing

No reliable external sexing character is documented for N. nigroris in the consulted sources, and colour differences between juveniles and adults are age-related. As in related damselfishes, the nest-tending male is identified behaviourally during reproduction.

Conditioning

A species-specific conditioning protocol is not documented. N. nigroris feeds on algae, crustaceans and pelagic tunicates and salps and is usually solitary; a varied marine diet supports condition. Maintain stable reef parameters within the recorded ranges (temperature about 24–26 °C, pH 8.1–8.4).

Breeding Setup

Provide open rock in a coral-rich, reef-style layout resembling the species' lagoon and seaward-reef habitat, giving a male a defensible nest patch. Following the family pattern, the male clears an area of algae and invertebrates before spawning. Because adults are aggressive, generous space and broken sightlines reduce conflict.

Spawning Behavior & Trigger

Specific spawning triggers for N. nigroris are not documented. In Pomacentridae, ritualised courtship precedes spawning; the female lays a string of sticky eggs attached to the substrate and the male fertilises them externally. FishBase confirms the eggs are demersal and adhere to the substrate and that males guard and aerate them.

Egg & Fry Care

The male guards and aerates the clutch through incubation. At family level, eggs hatch over about two to seven days into transparent larvae roughly 2–4 mm long that disperse into a pelagic phase. This planktonic stage is the principal barrier to captive reproduction.