Taxonomy
- Kingdom: Animalia
- Phylum: Chordata
- Class: Actinopterygii
- Order: Labriformes (formerly Perciformes)
- Family: Labridae
- Genus: Chlorurus
- Species: C. gibbus (Valenciennes, 1840)
Common names
- Gibbous parrotfish
- Redfin parrotfish (regional usage)
Description
Chlorurus gibbus is a moderately large marine fish characterized by a laterally compressed body and a robust, beak‑like dental plate formed by fused teeth, a hallmark of parrotfishes. Adults typically attain a total length of 40–55 cm, though individuals up to 60 cm have been recorded. Coloration is variable and exhibits marked sexual dimorphism:
- Initial phase (female and non‑terminal males) – generally displays a brown to olive base colour with irregular dark bars and a yellowish or reddish hue on the dorsal fin.
- Terminal phase (fully mature males) – exhibits a more vivid palette, often featuring a bright red or orange ventral surface, a conspicuous blue or green patch on the head, and a darker, more pronounced banding pattern along the flanks.
The species possesses a single continuous dorsal fin with 10–12 spines and 12–14 soft rays, and a similarly structured anal fin. The caudal fin is lunate in shape.
Distribution and habitat
Chlorurus gibbus inhabits the tropical Indo‑Pacific region. Its range extends from the Red Sea and the eastern African coast (including Madagascar and the Seychelles) through the Indian Ocean to the western Pacific, reaching as far east as the Philippines, northern Australia, and the islands of the South Pacific. The species is typically associated with coral reef ecosystems, favoring lagoonal and seaward reef slopes, reef flats, and areas of scrubby coral at depths of 1–30 m.
Ecology and behavior
- Diet: Like other parrotfishes, C. gibbus is primarily herbivorous, grazing on epilithic algal films and detritus scraped from coral substrates using its powerful dental plate. Occasional ingestion of small invertebrates and coral polyps has been reported, but such items constitute a minor component of the diet.
- Reproduction: The species is a protogynous hermaphrodite; individuals first mature as females (initial phase) and may later transition to functional males (terminal phase) depending on social structure and population dynamics. Spawning occurs in aggregations, with broadcast release of pelagic eggs and larvae into the water column.
- Territoriality: Adult terminal‑phase males establish and defend feeding territories that can encompass several hundred square meters, often containing a high density of algal resources.
Conservation status
According to the International Union for Conservation of Nature (IUCN) Red List, Chlorurus gibbus is assessed as Least Concern. The species is widely distributed and does not currently face major global threats. Localized pressures include habitat degradation from coral bleaching, coastal development, and overfishing (including targeted capture for the aquarium trade in some regions).
Human interactions
Chlorurus gibbus is occasionally harvested for food in small‑scale coastal fisheries, where it is sold fresh or smoked. Its striking coloration also makes it a target for the marine aquarium trade, though it is less common in captivity than some other parrotfish species.
Research notes
Further studies are needed to quantify population trends across its range, evaluate the impacts of climate‑related reef decline, and monitor exploitation levels in regions where the species is harvested.
All information presented is derived from peer‑reviewed ichthyological literature and reputable conservation databases; where specific data are lacking, the entry notes the uncertainty accordingly.
