Holocentrus adscensionis

Squirrelfish | Cook | Longjaw Squirrelfish | Hardback Soldier | Holocentrus ascensionis
Holocentrus adscensionis
Holocentrus adscensionis, Abrolhos, Bahia, Brazil, Photo: Graham Edgar

Similar Species


Tropical Atlantic/Caribbean


Head and upper half of body red-brown, brown/yellowish stripes along body, white belly and tail base, first dorsal fin yellow with red or translucent tips on membranes, and often a curving white band on rear half of body. Similar H. rufus has paler first dorsal fin, and long, golden rear dorsal fin. A nocturnal species that is found in caves, crevices and under ledges in the reef during the day.


Max Size: 61 cm

Sea Temperature Range: 23.1-30.6°C

Depth: 1-240m

Habitat Generalization Index: 7.8

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: Frequent (16.3% 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 (11 per transect)

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

Edit by: Joe Shields