Brazilian damsel (Stegastes fuscus)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Ovalentaria incertae sedis · Family: Pomacentridae · Genus: Stegastes.

Accepted name: Stegastes fuscus · Authority: (Cuvier, 1830) · Taxonomic status: accepted · AphiaID: 276669.

Synonyms and superseded combinations recorded for this taxon: Eupomacentrus fuscus (Cuvier, 1830); Pomacentrus fuscus Cuvier, 1830; Stegastes trindadensis Gasparini, Moura & Sazima, 1999.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=276669 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

Measured values published by FishBase for Stegastes fuscus. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 12.600000381469727 cm · Depth range: 1–15 m · Habitat zone: reef-associated · Body shape: fusiform / normal · Vulnerability index: 37.3 of 100.

FishBase notes: Adults inhabit shallow, coral or rocky bottoms and sometimes near the shore in areas with little visibility (Ref. 9626). Juveniles were collected from tide pools and on rocky Lithothamnion reefs; adults found up to 15 m depth (Ref. 40395). A diurnal species, adults feed on benthic algae, polychaetes and harpacticoid copepods (Ref. 9626); also consume hydroids and sponges and has been observed to feed on Abudefduf saxatilis eggs at night (Ref. 9626). 16:21 SL/TL (Ref. 9626). Oviparous, distinct pairing during breeding; eggs are demersal and adhere to the substrate; males guard and aerate the eggs (Ref. 205).

Source: FishBase species summary (SpecCode 3650) — https://www.fishbase.se/summary/Stegastes-fuscus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

14,891 georeferenced occurrence records for Stegastes fuscus are published through GBIF from 26 countries or marine areas. The map above plots 32 distinct locations from a sample of 3,000 records, omitting 22 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: Brazil (12,764); Puerto Rico (1,676); United States of America (132); Panama (88); Bahamas (47).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2398866) — https://www.gbif.org/occurrence/search?taxon_key=2398866&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=276669 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Stegastes fuscus (Cuvier, 1830) as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 154684) — https://www.iucnredlist.org/species/154684/0; GBIF IUCN Red List category endpoint (taxonKey 2398866) — https://api.gbif.org/v1/species/2398866/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

The colour of an adult dusky damselfish varies from brownish-olive to dark grey, with fine, darker-coloured, vertical stripes on the body. The fins are large with sometimes a blue rim around the edge of the dorsal and anal fins. The dorsal fin has 12 spines and 15-16 soft rays while the anal fin has two spines and 13-14 soft rays. The dusky damselfish can be distinguished from the very similar longfin damselfish (Stegastes diencaeus) by the shorter, less angular dorsal and anal fins. The maximum length is 15 cm, but 10 cm is a more typical length.

The juvenile dusky damselfish is pearly grey with blue spots on the top of its head. It has a large, blue-rimmed, black eyespot where the dorsal fin spines meet the dorsal fin soft rays, and a smaller, similarly coloured eyespot on the caudal peduncle. Some juveniles off the coast of southeastern Brazil have a vivid yellow and orange band on the back and dorsal fin.

Stegastes fuscus occurs in shallow waters off Brazil, where it is common on both rocky and coral reefs at depths down to 40 m. It is also reported from the Caribbean Sea, but another species, Pomacentrus dorsopunicans, possibly was misidentified there. Another population is reported from Senegal, but this lacks confirmation.

About 70% of the food consumed by the dusky damselfish consists of algae, mostly red, filamentous algae, but some calcareous algae are also eaten. The rest of their diet is small invertebrates. The feeding activities of the damselfish prevent coarser seaweeds, such as Jania spp., becoming dominant and greatly influences the structure of the benthic community.

The dusky damselfish is a territorial species. It guards part of the seabed and repels intruders, sometimes chasing away fish several times its own size. The richer the site was in suitable algae for feeding, the more aggressive the fish became. Besides members of its own species, the main species chased away were parrotfish, bluehead wrasse (Thalassoma bifasciatum), bicolour damselfish (Stegastes partitus) and ocean surgeonfish (Acanthurus bahianus). Certain other fish species, such as the smooth trunkfish (Rhinesomus triqueter) and the graysby (Cephalopholis cruentata), were not chased away. The author of the study surmised it was the food source rather than the geographical area being guarded, and these fish were not considered to be threats because they did not graze algae, instead feeding on small invertebrates. An alternative possibility was these fish benefited the dusky damselfish in some other way, such as by providing some protection against predators or by removing invertebrates that feed on algae.

Source: Wikipedia: Stegastes fuscus — https://en.wikipedia.org/wiki/Stegastes_fuscus (CC BY-SA 4.0). Accessed 2026-09-23.