Lactoria cornuta
Source: Kattegat Centeret - Kasper Hareskov Tygesen
Lactoria cornuta
Source: Kasper Hareskov Tygesen
Lactoria cornuta
Lactoria cornuta


Latin name Lactoria cornuta - (Linnaeus, 1758)
Common name Longhorn Cowfish
Family Ostraciidae - Lactoria
Origin East Indian Ocean, West Indian Ocean, Australia, Japan, The Red Sea
Max length 46.0 cm (18.1")

As aquarium fish

Minimum volume 1500 l (396 gal)
Hardiness Delicate
Suitable for aquarium Experience, preparation and extra care required
Reef safe Reef safe with luck
Aggressiveness Mostly peaceful but might be aggressive towards similar species


  • Larger crustaceans (Shrimp, crabs...)
  • Other invertebrates
  • Soft coral
  • Large polyp stone coral (LPS)
  • Macroalgae (Eg. seaweed / nori)
  • Small crustaceans (Krill, mysis, artemia...)

Poisonous skin

This species has a toxin in its skin, which it releases when highly stressed or dying.

This poison can kill all the aquatic life in the aquarium, if unlucky.

Threat towards invertebrates

This species likes eating crustaceans, small bivalves and the like.

Eats tubeworms

This species likes to eat tubeworms.

Demand a very large aquarium when fully grown

This species needs a very large aquarium when fully grown.

Exactly how big the aquarium should be is hard to say, but the size of this species is such, that it cannot normally be kept in a home aquarium.

Poor maneuverability

This species cannot maneuver in strong currents, especially so when small.

Pay particular attention to the pump’s water inlet as these fish in certain circumstances, can get stuck.


This species often has a fun and interesting personality.

Family description (Ostraciidae)

Boxfish(Ostraciidae) have a unique square shape and a particular way of swimming.
They have a rather special personality, which one quickly comes to love.

Boxfish live typically off a mixture of algae, coral polyps, zooplankton, and in some cases crustaceans.
They are not normally reef safe and when small will require gentle water circulation.

Boxfish can secrete a poison when stressed or if they die, which can in the worst case, kill the contents of a whole aquarium.
Never use the water the fish was transported in.


Aquarium trade Yes
Distribution Indo-Pacific: Red Sea (Ref. 12541) and East Africa (Ref. 12484) to the Marquesan and Tuamoto islands, north to southern Japan, south to Lord Howe Island (Ref. 9710).
English common names Longhorn cowfish, Long-horn cowfish, Long horned cowfish, Long-horned cowfish
Danish common names Kofisk
French common names Coffre, Poisson vache à longues cornes

References and further reading

About references

Bob Fenner. The Puffers Called Box-, Cowfishes, family Ostraciidae - Wet Web Media - (English)
Richard Aspinall. 2012. Oddballs for the Marine Aquarium - Tropical Fish Hobbyist - (English)

Froese, R. and D. Pauly. Editors. 2014. FishBase. World Wide Web electronic publication., version (08/2014).


eats shrimp, eats crab, eats bivalve clams mussels scallops, eats feather duster worm
Just a moment...
Just a moment...