Goldtail Half Blue Damsel

The Goldtail Half Blue Damsel (Chrysiptera arnazae) is a small reef damsel with a deep blue body and bright yellow tail, often showing extra yellow along the rear edges of its fins. It’s a hardy, reef-safe fish that brings constant movement around rockwork in mixed reefs and fish-only setups.

What You’ll Observe:

• Short patrol loops around a favorite rock or cave, with frequent hovering in the water column nearby
• Quick, confident feeding responses—often one of the first fish out at mealtime
• A “home base” that it returns to throughout the day, especially as the lights ramp down
• If kept with similar damsels, brief face-offs that usually end with quick retreats into separate rocks

To succeed, provide a reef structure with multiple crevices so it can choose a home base without taking over the whole aquascape. Offer a varied menu (quality pellets/flake plus frozen foods) and keep feeding consistent so it stays active and engaged. In community tanks, it does best when more peaceful fish are already established before it’s added.

Is it normal for this damsel to “claim” one rock and defend it?
Many keepers see a clear home base behavior where it patrols a small zone and chases passing fish, then quickly returns to its spot. Adding more caves and breaking up lines of sight with rock structure often spreads activity out.

Can I keep more than one Goldtail Half Blue Damsel together?
Groups tend to work best when they’re added at the same time and the tank has lots of separate hiding areas. In more open layouts, they’re more likely to focus on the same territory.

Does tail color reliably tell male vs. female?
Tail color can vary by species, collection area, and individual fish, so it’s not a dependable way to sex them. Pairing is usually easier by observing two fish that consistently share the same area without prolonged chasing.

What’s the best way to catch one if I need to move it later?
Most hobbyists have the best luck using a fish trap baited with food, placed near its regular home base. Patience helps—once it learns the trap is a feeding spot, it typically enters more readily.

Will it bother corals or clean-up crew in a reef?
In most reef tanks it ignores coral tissue and focuses on the water column and rockwork. Keeping it well-fed with a varied diet tends to keep its attention on prepared foods at mealtime.

We work with trusted suppliers who keep our specimens healthy and well-fed before shipping.