All fish / Plesiopidae

Marine Betta

Calloplesiops altivelis

Also known as comet, comet grouper, marine betta, betta grouper, sea betta, comet fish, calloplesiops, シモフリタナバタウオ, 珍珠龙, 珍珠大帆

A dark brown fish covered in small white spots, with very large dorsal, anal and pelvic fins and an eyespot near the back of the dorsal fin. When threatened it turns head down so its rear end and eyespot look like the head of a moray eel. Keepers like it for its striking look, hardy nature and calm, secretive behaviour on reef tanks.

Care at a glance

Care level

Moderate

Temperament

Semi

Adult size

16 cm

Temperature

24 to 28 °C

pH

8.1 to 8.4

Smallest tank

250 litres

Keep as

Single specimen; pairs only in a large tank

Diet

Carnivore: live or frozen shrimp, mysis, krill and small fish; may need weaning onto frozen foods

Swims

Middle of the tank

Lifespan

10 to 15 years

Water

Marine (saltwater)

Wild range

Indo-Pacific, from East Africa and the Red Sea to the Line Islands and Tonga

Breeding

Pairs lay egg masses in caves and the male guards them until they hatch. It has been bred in captivity, but rearing the larvae is difficult and rarely achieved by hobbyists.

Good to know

It will eat small fish and shrimp that fit in its mouth, and it is shy, so avoid boisterous tankmates and provide caves. Usually safe with corals.