Western Pacific from the Coral Sea to Samoa; reefs and lagoons.
Water
saltwater
Maximum size
8 cm
Temperature
24–27°C
pH
8.1–8.4
Hardness
Salinity SG 1.023–1.026
Minimum tank
100 litres
Care level
beginner
Temperament
aggressive
Reef safe
yes
Care
Tank: a reef or fish-only aquarium with plenty of rockwork. Because of its aggression the article recommends a large tank. Tank: an estimated minimum of about 100 litres (our estimate from the adult size and habits, not a figure from the sources). Water: the sources give no species-specific figures, so the values here are general marine aquarium guidance, not species-specific: 24–27 °C, pH 8.1–8.4 and specific gravity 1.023–1.026. Keep conditions stable with good filtration and regular water changes. Behaviour: very aggressive towards other small fish, especially other damsels and clownfish, once mature. Identification: striking bright blue with yellow on the belly and tail. Up to 8 cm. Trade: a popular, hardy beginner fish. IUCN: Least Concern. Not CITES-listed. Sources: Wikipedia, List of marine aquarium fish species (en.wikipedia.org/wiki/Listofmarineaquariumfishspecies); Wikipedia (en.wikipedia.org/wiki/Chrysipterataupou). Checked October 2026.
Diet
An omnivorous damsel. Offer frozen mysis and brine shrimp, flake, small pellets and algae-based food.
Breeding
Pairs form to breed and the male guards and tends the eggs.
Compatibility and tank mates
Reef safe. Do not keep with other damsels or clownfish in small tanks; add it last and choose robust tankmates.
Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.
About Aquatic-Auctions
Aquatic-Auctions (aquatic-auctions.com) is a UK online marketplace for aquarium and pond livestock and equipment: tropical and marine fish, corals, shrimp, snails and other invertebrates, aquatic plants, tanks, filtration, lighting and food.
Items are sold by auction, buy it now or classified advert, by hobbyist and business sellers in the UK.
Buyers pay sellers directly; Aquatic-Auctions does not hold the money. Hobbyist sellers must offer PayPal and may also take cash on collection. Business sellers take PayPal (required) or cash on collection, and bank transfer only once they have a seller rating of 50 out of 100, a company and pet-selling licence checked by Aquatic-Auctions, a bank account in the company's name, and bank details approved by Aquatic-Auctions.
Buyers are told to pay by PayPal Goods & Services, never PayPal Friends and Family, gift cards or crypto.
Live fish and other vertebrates must be sent by specialist live-animal couriers (for example APC Overnight or DX Express), never by Royal Mail. Some invertebrates and plants may go by Royal Mail Special Delivery or 1st Class within its rules.
Banned and invasive species (for example those on the GB invasive species lists) cannot be listed, and sellers must meet the site’s animal welfare standards.
Members must be 16 or over to buy (16 and 17-year-olds with a parent or guardian’s agreement); sellers must be 18 or over.
Business sellers show their address, company details and pet-selling licence to buyers. Seller ratings run from 0 to 100: +1 for each positive feedback, −1 for each negative.
The site includes a free community species wiki with care guides (water parameters, tank size, diet, temperament, breeding).
Aquatic-Auctions is run by Etavonni Tech Limited trading as Aquatic-Auctions (company number 10204188), Aldershot, Hampshire, UK. Contact: info@aquatic-auctions.com.