All fish / Ostraciidae

Humpback Turretfish

Tetrosomus gibbosus

Also known as humpback turretfish, thornback boxfish, thornback cowfish, helmet cowfish, camel cowfish, humpback boxfish, turret boxfish, hunchback boxfish, ラクダハコフグ, 驼背三棱箱鲀, 驼背箱鲀

A small boxfish with a rigid, triangular bony shell that rises into a tall, spiked hump on the back, usually tan to yellowish with pale blue or white spots. Keepers choose it for its odd shape and slow, hovering swimming over sand and seagrass.

Care at a glance

Care level

Hard

Temperament

Peaceful

Adult size

20 cm

Temperature

22 to 27 °C

pH

8.1 to 8.4

Smallest tank

400 litres

Keep as

Singly, or one per large tank

Diet

Omnivore: mysis, chopped shellfish, krill, small invertebrates, algae and seaweed-based foods

Swims

Bottom of the tank

Lifespan

5 to 10 years

Water

Marine (saltwater)

Wild range

Indo-West Pacific: Red Sea and East Africa to Southeast Asia, northern Australia and southern Japan; Lessepsian migrant in the eastern Mediterranean

Breeding

It scatters pelagic eggs after pairing at dusk, and it has not been bred reliably in home aquariums.

Good to know

Like other boxfishes it can release ostracitoxin when stressed or dying, and this can wipe out a whole tank, so it needs careful handling and a large, stable system. Its slow feeding means it does poorly with fast or nippy tankmates, and it may pick at small invertebrates.