Glass eye squirrelfish (Heteropriacanthus cruentatus) care guide

Group
Marine fish
Family
Priacanthidae (bigeyes)
Water
saltwater
Maximum size
30 cm
Temperature
24–27°C
pH
8.1–8.4
Hardness
Salinity SG 1.023–1.026
Minimum tank
450 litres
Care level
intermediate
Temperament
semi_aggressive
Reef safe
with_caution

Care

Tank and decor: a nocturnal fish with large eyes that hides in caves and under ledges by day. Provide plenty of shaded overhangs, subdued lighting and open space to swim at night. Minimum tank: about 450 litres (an estimate based on its 30 cm adult size and active night-time swimming). Water: our 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 nitrate low and the water well oxygenated. Identification: despite the name used in the list, this is a bigeye (family Priacanthidae) rather than a true squirrelfish. It is reddish to silvery and can change colour quickly, often becoming blotched. The list gives a maximum size of 30 cm. Sources: Wikipedia, List of marine aquarium fish species (en.wikipedia.org/wiki/Listofmarineaquariumfishspecies). Checked October 2026.

Diet

Carnivorous and mainly nocturnal, feeding on small crustaceans and small fish. Give meaty frozen foods such as mysis, krill, chopped prawn and lancefish. Feed in the evening or under dim light at first, as they are most active then.

Breeding

Our sources for this page do not describe breeding. Fishes of this kind spawn in open water and have planktonic larvae, and they are not bred in home aquaria.

Compatibility and tank mates

Reef safe with caution: it leaves corals alone but will eat small shrimps, crabs and fish that fit in its mouth. Keep it with fish of similar or larger size. It is usually peaceful towards fish it cannot eat, but some squirrelfishes defend a favoured cave.

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.