About Acanthochromis polyacanthus (Bleeker, 1855)
Maximum Size
Adult spiny chromis (Acanthochromis polyacanthus) can reach a maximum total length of 14 centimetres (5.5 inches).
Fin Structure
Their fins have 17 dorsal spines, 14 to 16 dorsal soft rays, 2 anal spines, and 14 to 16 anal soft rays.
Base Body Coloration
The front half of the body is gray, and the back half is white.
Geographic Color Variation
The ratio of gray to white coloring varies between different reef populations, because there is little interbreeding between reefs, as this species has no pelagic larval stage.
Ontogenetic Color Shift
As the fish matures, its gray color can shift from blue-gray to brown.
Fin Margin Coloration
The edge of the dorsal fin along the top and the edge of the anal fin along the bottom are black.
Alternative Color Morph
Some individuals have an overall gray body with a yellow horizontal stripe running along the midline of the body.
Native Range
The spiny chromis is native to the western Pacific Ocean.
Confirmed Distribution
Its confirmed distribution includes western and central Indonesia, Papua New Guinea, northern Australia, all islands of the Philippines except Luzon, and Melanesia.
Primary Habitat
This species lives primarily on coral reefs.
Depth Range
It can be found at depths between 1 and 65 metres (3.3 to 213.3 feet), though it most commonly occurs at depths from 4 to 20 metres (13 to 66 feet).
