Stegastes nigricans

Dusky Gregory | Dusky Damselfish | Dusky Farmerfish | Mamo
Stegastes nigricans
Stegastes nigricans, adult, Great Barrier Reef, Cairns, QLD, Photo: Andrew Green
Stegastes nigricans
Stegastes nigricans, adult, Photo: Rick Stuart-Smith
Stegastes nigricans
Stegastes nigricans, QLD, Australia, Photo: Rick Stuart-Smith
Stegastes nigricans
Stegastes nigricans, adult, Photo: Rick Stuart-Smith
Stegastes nigricans
Stegastes nigricans, juvenile, North WA, Australia, Photo: Andrew Green
Stegastes nigricans
Stegastes nigricans, adult, Naigani Is, Fiji, Photo: Andrew Green
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Stegastes nigricans
Stegastes nigricans
Stegastes nigricans
Stegastes nigricans
Stegastes nigricans
Stegastes nigricans

Distribution

Tropical Indo-Pacific


Description

Black spot below rear dorsal fin, mauve streak below eye, and black spot at pectoral fin base. Territorial, farming turf algae on the base of branching corals. Light bar across middle of body and stripe from mouth to pectoral fin, sometimes occuring in courting males. S. punctatus (Bluntsnout Gregory) has larger, less distinct black spot under dorsal fin, and darker scale margins.


Information

Max Size: 14 cm

Sea Temperature Range: 22.1-31.2°C

Depth: 1-12m

Habitat Generalization Index: 18.68

Also referred to as the SGI (Species Generalisation Index), this describes the habitat niche breadth of the species. Species with values less than 15 are found in a relatively narrow range of reef habitat types (specialists), while those over 25 may be found on most hard substrates within their range (generalists). Learn more here.


Conservation and Rarity

IUCN Status: Not Evaluated

Occurrence: Common (21.5% of sites)

Occurrence describes how often the species is found on surveys within its distribution. It is calculated as the % of reef sites surveyed by RLS divers across all the ecoregions in which the species has been observed

Abundance: Many (23 per transect)

Abundance is calculated as the average number of individuals recorded per RLS transect, where present.


Edit by: RD Stuart-Smith, GJ Edgar, AJ Green, IV Shaw. 2015. Tropical Marine Fishes of Australia. Reed New Holland