Bicolor Angelfish

The bicolor angelfish is one of the easiest dwarf angelfish to recognize, thanks to the sharp color transition that divides its body in the middle: the head and front half are bright yellow, the rear half deep royal blue; a blue saddle over the eye and a yellow tail complete the pattern. The spine on the gill cover, as in all dwarf angelfish, can get caught in a net.

Almost all individuals are wild-collected. It is more sensitive to collection and shipping stress than other dwarf angelfish; choose a lively, brightly colored individual that you have seen eating in the store for at least a few days. Once settled it is long-lived; it has been reported to live up to 13 years.

It lives in lagoons, channels and on sheltered reef slopes of the Indo-Pacific, in coral and rubble areas. It usually moves about in pairs or small groups, darting from one hiding place to another. In the wild it feeds on algae, small crustaceans and worms.

• Volume: at least 250 liters; live rock with many caves and passages.
• Water: salinity 1.023–1.026 specific gravity, pH 8.1–8.4, temperature 24–27°C. Stable water parameters and low nitrate.
• Maturity: an aquarium at least 6 months old, with algae and small organisms on its rocks.
• Reef compatibility: reef safe with caution. Soft corals and SPS are generally safe; LPS corals, zoanthids and the mantles of Tridacna clams may be picked at.

Omnivorous. Offer angelfish foods containing spirulina and seaweed, frozen mysis and brine shrimp, chopped seafood and dried seaweed. Feed small amounts 2–3 times a day. If a new arrival refuses food, frozen mysis and the algae on live rock stimulate its appetite.

It starts out shy and opens up as it feels safe. It defends its territory; it may be aggressive toward other dwarf angelfish, especially those of similar colors. It causes no problems with larger fish of a different shape.

Good companions: clownfish, tangs, anthias, fairy wrasses, cardinalfish, gobies, cleaner shrimp.

Avoid: a second dwarf angelfish (except in a very large aquarium), large aggressive species, lionfish.

Keep a single individual in the aquarium. It is a species that starts out as female, and the sex change takes about 2–3 weeks; in a very large aquarium a pair can be formed by adding two juveniles of clearly different sizes together.

Pairs rise into the water column in the late afternoon and release pelagic eggs. Spawning can be seen in the aquarium, but raising the fry takes expertise.

• Losses during acclimation: loss of appetite in the first weeks is the biggest risk.
• Marine ich and velvet: quarantine is recommended.
• Copper sensitivity: dwarf angelfish may lose their appetite during copper treatment; the dose should be monitored carefully.

The sexes cannot be reliably told apart externally; in a pair, the larger one is usually the male.