Neon Damselfish Identification Guide
Recognize this iridescent reef fish by its slim purple-blue body and small yellow patch at the tail base.
Read the full Neon Damselfish encyclopedia entry →
Key identification features
- Slender, streamlined body with an iridescent purple-blue sheen
- Small yellow patch limited to the tail base (caudal peduncle), with the rest of the tail remaining blue
- Deeply forked tail fin
- Small size, typically 2-3 inches (5-7 cm)
- Coloring can shift between blue and violet depending on the light angle
Common look-alikes
- Yellowtail blue damselfish has a fully bright yellow tail fin, not just a small patch at the base, making tail extent the key separator.
- Blue devil damselfish is a deeper-bodied, more solid blue fish with no yellow anywhere on the tail.
- Springer's damselfish has a grey-white body with a bold black eye mask rather than the neon damselfish's uniform iridescent blue.
Where you'll see one
Neon damselfish are found on rubble flats, sandy patches, and reef edges throughout the Indo-Pacific, often in small loose aggregations hovering just above the bottom. They feed on plankton in the water column and duck into nearby rubble or small crevices whenever a predator passes by.
Frequently asked questions
How do I tell a neon damselfish from a yellowtail blue damselfish?
The neon damselfish has only a small yellow patch at the base of an otherwise blue tail, while the yellowtail blue damselfish has a solid, fully yellow tail fin.
Why does this fish look more purple in some photos?
Its iridescent blue coloring shifts toward violet or purple depending on the lighting angle, so relying on the yellow tail-base patch is a more consistent ID cue than exact hue.