Yellow-Axil Chromis

The Yellow-Axil Chromis is a handsome schooling damselfish recognized by the distinctive yellow spot at the base of each pectoral fin, from which it derives its common name. The body displays a subtle silvery-blue to grayish-green coloration with a gentle iridescent quality that shifts beautifully under aquarium lighting. At a maximum size of approximately 5 inches, it is moderately sized for a chromis but maintains the peaceful, schooling temperament that makes this genus so popular in reef aquariums.

In the wild, Chromis xanthochira is found on outer reef slopes, drop-offs, and lagoon margins throughout the Indo-Pacific, often at moderate depths where it forms aggregations above coral formations. These schools feed on zooplankton and phytoplankton carried by reef currents, creating the characteristic hovering clouds of small fish that are such a hallmark of healthy reef environments. The species often schools alongside other Chromis species and damselfish, and the yellow axillary marking serves as a species-recognition signal within mixed groups.

The Yellow-Axil Chromis is an excellent community reef fish that offers hardiness, peaceful behavior, and attractive natural schooling displays. It is one of the easier marine fish to maintain, readily accepting a wide variety of prepared and frozen foods. For the most natural behavior and visual impact, keep in groups of 5 or more in a suitably spacious aquarium. Like other Chromis species, small groups may develop a dominance hierarchy that leads to gradual attrition; larger schools help distribute aggression. The species is completely reef-safe and poses no threat to corals or invertebrates.