Pearlscale Butterfly

The Pearlscale Butterfly (Chaetodon xanthurus) has a white, crosshatch “pearlscale” pattern with a dark eye band, plus a yellow-to-orange rear body and tail. It’s a diurnal reef fish from the central Indo-Pacific that spends the day cruising and picking at rock surfaces.

What You’ll Observe:

• Steady, deliberate swimming through open lanes, then short laps around rockwork
• Frequent “pecking” at the rock face while it grazes and explores
• A routine of staying active through the daytime and settling into the rockwork at night
• More confident feeding responses as it learns your tank’s feeding schedule

Provide plenty of live rock with sheltered pockets, while keeping clear swim space along the front and sides. Offer a varied mix of meaty frozen foods plus algae-based items (like nori on a clip) so it can graze between feedings. With consistent conditions and calm tankmates, it settles into a predictable daily pattern and becomes a regular presence at the glass.

How do people get a Pearlscale Butterfly to accept flakes or pellets?
Start with a “sure thing” frozen food and mix in small amounts of the dry food so it gets sampled in the same bites; many hobbyists repeat this for a few weeks until dry foods are recognized as food.

Why does it keep picking at the rocks all day?
This species naturally forages by pecking at surfaces, so repeated grazing passes are a normal part of its daily routine in an established tank.

Does it do better with lots of open water, or lots of caves?
Most keepers see the best behavior with both: open lanes for cruising plus multiple shaded pockets in the rockwork for resting and “resetting” between laps.

Is it normal for a Pearlscale Butterfly to “patrol” one side of the tank?
Yes—many individuals establish a preferred loop or territory and will repeatedly cruise that route, especially when lights are on and it’s in daytime foraging mode.

Will it eat algae sheets (nori) like a tang?
Some learn to pick at nori readily once it’s clipped in a consistent spot, and it can become a simple way to add grazing time between feedings.

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