A reef fish shaped by numbers and hierarchy
Where Maldivian reefs fall away into deeper blue, clouds of scalefin anthias gather in dazzling abundance. Known locally as Kashikeyo mas, this species is the most common anthias on shallow reefs, reaching lengths of up to 15 centimeters.
Seen from a distance, their aggregations resemble drifting sparks—constantly shifting, constantly feeding, and always alert. These fish rarely settle on the reef itself, instead claiming the open water just in front of drop-offs, where plankton-rich currents rise from the deep.
A body shaped by exposure and flow
The scalefin anthias is built for life in exposed reef zones. Its fins are heavily scaled, its tail lunate and powerful, and its body slightly deeper than many related species. The dorsal fin carries 10 spines and 16–18 soft rays, while the anal fin bears 3 spines and 6–7 rays, providing control in strong, variable currents.
Sexual differences are dramatic. Females—far more numerous—are orange-yellow, with scales delicately edged in lavender. Males are vivid fuchsia, each scale marked with a yellow spot, and their third dorsal spine elongates into a flowing banner. These visual signals reinforce a strict social hierarchy, with one dominant male presiding over a group of females.
A home shaped by depth and evening light
Scalefin anthias are most common on reefs shallower than 35 meters, especially along slopes and drop-offs. As daylight fades and plankton thickens in the water, feeding activity intensifies. In the golden light of evening, entire shoals rise higher into the water column, flashing colour as they feed.
Distributed widely across the Indo-Pacific, this species is a defining feature of tropical reef scenes—and a favourite among divers for its sheer abundance and colour.
A common fish that defines the reef’s rhythm
Though often described as common, the scalefin anthias plays an essential ecological role. By feeding on plankton and moving constantly between reef and open water, it transfers energy through the reef system, supporting predators and enriching coral ecosystems.
In the Maldives, to look out over a reef edge is often to see these fish suspended in motion—proof that life on coral reefs is not only built on stone and coral, but also on movement, light, and numbers.
Species snapshot
- English name: Scalefin anthias
- Local name: Kashikeyo mas
- Family: Serranidae
- Maximum size: 15 cm
- Habitat: Coral reefs to 35 m
- Diet: Plankton
- Distribution: Indo-Pacific
Reference
M.R.S. (1997). Fishes of the Maldives. Marine Research Section, Ministry of Fisheries and Agriculture, Republic of Maldives. 408 pp.
