Care
In the wild, Emperor Damselfish may be found within bays and sheltered fringing reefs usually amongst corals, feeding mainly on zooplankton in the water column.
The smallest and least aggressive of the yellow-tailed damsel complex, arnazae seem to be monogamous in the wild and this behaviour carries over into their aquarium. Like all damsels (including clownfish) the most stable groups come from introducing animals with a size difference and in this case, the dominant fish will become male. Kept singly, a bored damsel may be more inclinded to interact with tankmates of different species but when added to a spacious tank that allows individuals to avoid one another, there's no reason why two or more can't be housed together if simultaneously. Potentially a lone mature fish can be paired by adding a significantly smaller specimen which will then mature as female, providing the aquarium is large enough to enable the newcomer to escape the larger fish's core territory. Unlike clownfishes, paired damsels like to have some personal space and will operate within a larger territory, the male guarding a spawning site at its center. Tankmates can include species such as firefish and cardinals, with other species of damsels best avoided unless the aquarium is very large.
This species is entirely trustworthy in a reef aquarium and will earn its keep by eating nuisance flatworms. The male will usually adopt a suitable small cave or rock crevice as a spawning cave, so in more open reefscapes some digging may take place as a suitable shelter is adapted if absent.
This vibrant species was formally described in 2010, with the fish previously being known as Chrysiptera cf. parasema in reference to the close resemblance to the Yellow Tail Blue Damselfish (C. parasema). C. arnazae may be told apart from C. parasema as the former not only has yellow on the caudal fin and caudal peduncle, but it also displays yellow on the posterior margins of the anal, dorsal, and pelvic fins.
Feeding
Offer a varied diet consisting of small frozen foods such as Spirulina-enriched brineshrimp, Mysis shrimp and finely chopped krill, plus marine flake food and herbivore rations. Feed small amounts 3 times per day. This species also eats nuisance flatworms.
Breeding
This species readily spawns in the home aquarium but rearing the planktonic young requires specialised equipment and techniques. Males prepare their chosen spawning site for females to deposit their adhesive, demersal eggs. Once the eggs are laid the male will quickly fertilize them and aggressively defend them from any intruders. He will also aerate the eggs until they hatch. Due to economic factors, Chrysiptera damsels aren't often reared in captivity but techniques similar to clownfish should prove successful.
