Pycnochromis iomelas

Half-and-half puller | Chromis iomelas
Pycnochromis iomelas
Pycnochromis iomelas, adult, Photo: Rick Stuart-Smith
Pycnochromis iomelas
Pycnochromis iomelas, West Islet, Coral Sea, Photo: Rick Stuart-Smith
Pycnochromis iomelas
Pycnochromis iomelas, Frederick Reef, Coral Sea, Photo: Graham Edgar
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Pycnochromis iomelas
Pycnochromis iomelas
Pycnochromis iomelas


Tropical Indo-Pacific


Straight division between black and white above front of anal fin. Restricted to eastern Australia and Pacific, whereas Pycnochromis fieldi (Two-tone Puller) occurs in the Indian Ocean, and Chromis dimidiata (Chocolate-dip chromis occurs in the Red Sea. 


Max Size: N/A cm

Sea Temperature Range: 23-29.9°C

Depth: 1-35m

Habitat Generalization Index: 9.5

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 (35.8% 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: Large aggregations (105 per transect)

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