Blue Green Chromis Identification Guide
Identify the Blue Green Chromis by its iridescent blue-green body, forked tail, and dense schooling habit.
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Key identification features
- Small, slender body with iridescent blue-green shimmer across the sides
- Pale, almost translucent tail fin that is deeply forked
- Slightly darker dorsal edge blending into the lighter belly
- Large eyes and a small, upturned mouth suited for picking plankton
- Compact size, usually under 8 cm
- Schools in tight, synchronized groups above the reef
Common look-alikes
- Green Chromis: appears nearly identical but often shows a slightly more solid green tone without the added blue iridescence
- Blue Damselfish: is more solidly and deeply blue without the pale, forked tail of the chromis
- Yellowtail Damselfish (juvenile): has a bright yellow tail contrasting with a blue body, unlike the pale tail of the Blue Green Chromis
Where you'll see one
Blue Green Chromis hover in large schools just above branching coral heads on shallow reefs and lagoons throughout the Indo-Pacific, darting into the coral for shelter the instant a predator approaches, and feeding on drifting plankton carried past the reef by passing currents.
Frequently asked questions
How do I tell a Blue Green Chromis from a Blue Damselfish?
Look at the tail and overall tone: the Blue Green Chromis has a pale, deeply forked tail and a lighter iridescent shimmer, while the Blue Damselfish is a more solid, deeper blue throughout.
What behavior helps identify a Blue Green Chromis?
Watch for dense, synchronized schools hovering just above branching coral, ready to dive into the coral branches together when startled.