Yellowbelly Damselfish Identification Guide
Spot this reef damselfish by its sharp top-to-bottom color split of dark blue-grey above and bright yellow below.
Read the full Yellowbelly Damselfish encyclopedia entry →
Key identification features
- Upper body and back dark blue-grey to olive
- Lower body and belly bright, solid yellow, with a clean horizontal boundary between the two zones
- Small, deep-bodied and laterally compressed, typical of Pomacentrus damselfish
- Forked tail, often carrying a hint of the yellow ventral color
- Small size, generally 2-3 inches (5-8 cm)
Common look-alikes
- Bicolor damselfish also splits into two colors, but the division runs front-to-back (pale head, dark tail) rather than top-to-bottom.
- Yellowtail blue damselfish is blue over the entire body except for a solid yellow tail, unlike the belly-only yellow of this species.
- Whitebelly damselfish shows a similar horizontal split but with a pale white or cream belly instead of bright yellow.
Where you'll see one
Yellowbelly damselfish live on coral reef slopes and rubble patches across the tropical Indo-Pacific, often in small loose aggregations just above the reef structure. They feed on plankton drifting in the current and dive for cover into coral or rubble crevices when threatened.
Frequently asked questions
How do I tell a yellowbelly damselfish from a bicolor damselfish?
The yellowbelly damselfish splits color top-to-bottom, with a dark back and yellow belly, while the bicolor damselfish splits front-to-back, with a pale head and dark rear body.
Does the yellow coloring extend onto the tail?
The tail can carry a hint of yellow, but the main identifying feature is the bright yellow lower body and belly contrasting sharply with the dark upper body.