The spiny chromis

spiny chromis

Q: Where lives the spiny chromis in nature?

Acanthochromis polyacanthus frequents coastal and offshore coral reefs, from 1 to 65 m deep, but mostly between 4 and 20 m. It is encountered in lagoons, harbors, and on outer reef slopes. It favors coral areas where it establishes its reproductive territories and where the young find shelter.

Q: How to recognize the spiny chromis ?

This fish reaches a maximum length of 16 cm. Its body is tall and laterally compressed. It has 17 dorsal spines, followed by 14 to 16 soft rays, and 2 anal spines with 14 to 16 soft rays. The color pattern varies among geographical populations, leading to taxonomic uncertainties regarding some local forms.

✓ Acanthochromis polyacanthus

Family	Pomacentridae
Genus	Acanthochromis
IUCN category (World)	LC

Introduction

Descriptor : Bleeker, 1855

Acanthochromis polyacanthus, or spiny chromis, is a damselfish widely distributed in the Indo-Australian archipelago and Melanesia. It is characterized by a unique reproductive strategy among pomacentrids: it does not have a pelagic larval stage and provides extended parental care for the fry.

Who is it?

Morphology

Average size

12 cm
Maximum size

14 cm

Average size

12 cm
Maximum size

14 cm

How to recognize This fish ?

This fish reaches a maximum length of 16 cm. Its body is tall and laterally compressed. It has 17 dorsal spines, followed by 14 to 16 soft rays, and 2 anal spines with 14 to 16 soft rays. The color pattern varies among geographical populations, leading to taxonomic uncertainties regarding some local forms.

Sexual dimorphism

No marked sexual dimorphism is reported. Males and females have a similar morphology, and the distinction is primarily based on reproductive behavior, particularly the male's guarding and fanning of eggs.

Behaviour & Life cycle

diet

omnivorous
Sociability

living as a couple or in a group
territorial

Yes
Way of living

diurnal

A gregarious species in its juvenile state, the spiny chromis forms small groups as it grows. Adults live in monogamous pairs and become territorial during reproduction.

Reproduction

Reproduction

ovipare qui pond sur substrat caché

An oviparous species, it lays demersal eggs attached to the substrate. Reproduction occurs in monogamous pairs, with the male fanning and protecting the eggs until hatching. Remarkably, the young do not go through a pelagic larval stage: they remain directly associated with the parental territory, benefiting from active parental protection.

Harmless species

This species does not represent any particular threats to humans when encountered in its natural environment.

Origin and distribution

Natural range

Invasive range

Mixed / unknown area

Origin

Great Barrier Reef Philippine Sea Indonesian seas Western Tropical Pacific Ocean

islands

New Caledonia French Polynesia

Geographic distribution & Conservation

The species is widely distributed in the western Pacific. It is found from Indonesia and the Philippines to northern Australia and Melanesia, including Papua New Guinea, the Solomon Islands, Vanuatu, and New Caledonia. It has also been reported in the Caroline Islands.

Conservation status of populations (IUCN)

World : LC

Where to see this species?

What is its habitat?

Natural environment characteristics

Temperature

25 - 29 °C
Depth

1 - 65 m

Biotope presentation

Acanthochromis polyacanthus frequents coastal and offshore coral reefs, from 1 to 65 m deep, but mostly between 4 and 20 m. It is encountered in lagoons, harbors, and on outer reef slopes. It favors coral areas where it establishes its reproductive territories and where the young find shelter.

Species of the same biotope

To go further

Species of the same family

Plectroglyphidodon imparipennis Pomacentridae

To read on the web

Sources & Contributions

Participation & Validation

The Fishipedia team and specialist contributors are committed to providing high-quality content. However, although the information comes from scientific sources or testimonials from specialists, the cards may contain inaccuracies.

Benoit Chartrer

Translation

Translation done with the valuable contribution of our translators, who make this information available to a wider audience. We sincerely thank them for their commitment.

Marine Kassel

Bibliographic references