Fish
Dusky Damselfish
Stegastes adustusAlso known as Scarlet-backed Demoiselle
Dusky damselfish fiercely defend small reef territories, tending private algae lawns that they cultivate by weeding out unpalatable turf species. Adults are relentless guards, boldly charging much larger fish, sea urchins, and even passing snorkelers who encroach on their grazing boundaries. Males prepare cleaned rock surfaces to attract mates and fan the developing egg clutches continuously until hatching.
Reef FishTerritorialMarine
—observations
—countries
—peak records
Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Diet & preyFilamentous Algae, Copepods, Organic Detritus
Predators
- Nassau Grouper
- Great Barracuda
- Bar Jack
ThreatsCoral bleaching, reef degradation, sedimentation, and coastal development
HabitatsShallow, wave-swept coral reefs, rocky shorelines, and surge zones
Life span5–10 years
Classification
- OrderPerciformes
- FamilyPomacentridae
- GenusStegastes
- SpeciesStegastes adustus
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Safe to observe at a normal distance.
Responsible observation
- Snorkeling Observation: Look into shallow surge channels, where individuals perch boldly atop coral heads.
- Respect Boundaries: Stay clear of their cultivated algae patches to avoid provoking feisty territorial charges.
Image unavailableSame Genus 
Same Genus (c) Pauline Walsh Jacobson, some rights reserved (CC BY), uploaded by Pauline Walsh Jacobson · cc-by
Same Genus (c) LASZLO ILYES, some rights reserved (CC BY) · cc-by
Competitor (c) Greg Grimes, some rights reserved (CC BY-SA) · cc-by-sa
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