Tank and decor: a large tank with open swimming space and calm tankmates. Often sold small, but it grows to 46 cm. The tank size given is an estimate based on its adult size. Little is given in our sources beyond the aquarium list; the notes below are general guidance for this kind of fish. Water: the sources give no species-specific figures, so the values here are general marine aquarium guidance: 24–27 °C, pH 8.1–8.4 and specific gravity 1.023–1.026. Keep nitrate low and the water well oxygenated. Toxin warning: boxfish and cowfish can release a toxin from the skin when stressed or dying, which can kill every fish in the tank. Handle gently, ship them in their own bag and run activated carbon. Do not eat them. Identification: greyish tan with long horns above the eyes and under the tail fin. Selling: our policies require the adult size and long-term tank needs to be stated clearly in the listing. Large fish must travel by a specialist live-animal courier (see the Livestock shipping guide). Sources: Wikipedia, List of marine aquarium fish species (en.wikipedia.org/wiki/Listofmarineaquariumfishspecies). Checked October 2026.
Diet
Our sources give no diet. Boxfish pick at small invertebrates; offer a varied diet of small meaty foods and some algae.
Breeding
Not described in our sources.
Compatibility and tank mates
The list says "with caution" for reefs: boxfish may pick at invertebrates and small corals. Keep with peaceful fish that will not harass it.
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.