Not furry, but we like them anyway.
Longhorn Cowfish
Lactoria cornuta
Also called Horned boxfish, Long-horn cowfish
From Indo-Pacific: Red Sea and East Africa east to the Marquesas and Tuamotu islands, north to southern Japan and south to Lord Howe Island1
At a glance the quick version
Saltwaterfish.com says 10 or more years with good care
Looks how to spot one
Boxfish with a rigid carapace and two long horns
The body is a hard box made of fused six-sided bony plates, with two long horns pointing forward above the eyes. It is yellow to olive with white or bluish spots. The horns are mostly hollow and can grow back if damaged.21
Personality what they are like
Generally peaceful but can be territorial toward other cowfish or similar boxfish. Adults are shy in the wild.312
Daily activity how busy a day looks
A slow swimmer that moves mainly by its fins and tail tip. It prefers gentle water flow.23
Grooming and care the hands-on bits
Rated expert-only care. Not reef-safe, as it may nip corals and small invertebrates. It is a slow eater, so avoid fast, pushy tankmates that would out-compete it at feeding time.3
Home where they are happiest
A very large tank of at least 180 US gallons (about 680 L) for one fish, with low flow. Saltwater at 22 to 26 °C (72 to 78 °F), pH 8.1 to 8.4, specific gravity 1.020 to 1.025. Wild adults live over sand and mud in sheltered bays, harbours and estuaries at about 1 to 50 m, and young fish use shallow brackish flats.31
Food basics what goes in the bowl
An omnivore. Offer meaty foods such as shrimp, clams, mussels and bloodworms, plus algae-based foods. Wild fish blow jets of water into the sand to uncover small invertebrates.321
Company who they like around
Adults live alone, while juveniles gather in small groups. In aquariums keep one per tank.13
The story where it all began
Carl Linnaeus described the species in 1758 as Ostracion cornutus. The genus name Lactoria means milk cow, a nod to its cow-like horns, and cornutus means horned. It is the best-known cowfish in the aquarium hobby.2
Fun facts for the dinner table
- 1
It blows water jets into the sand to flush out hidden food.2
- 2
Its horns are hollow and can regrow within a few months.2
- 3
It makes humming and clicking sounds with muscles attached to its swim bladder.2
- 4
Its rigid box-shaped body means it swims mainly with its fins, a style called ostraciiform swimming.2
- 5
Females average slightly larger than males.2
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 2023)1
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Longhorn Cowfish. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- FeedingSmall amounts once or twice a dayevery day
- Temperature checkevery day
- Salinity checkevery week
- Top-upTop up evaporation with fresh RO water, not salt waterevery day
- Water testevery week
- Water changeAbout 10 to 20% of the waterevery 2 weeks
- Glass cleanevery week
You might also like
Dogface Puffer
Valentini Puffer
Picasso TriggerfishLike what we are building? Buy us a coffee.
The breed atlas is free for everyone, with a source on every fact, and it will never show ads. If it helped you, a small tip keeps the research going. Any amount is lovely, and no is a perfectly fine answer too.
Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.
- FishBase: Lactoria cornuta, Longhorn cowfish fishbase.seused for distribution, length, depth, habitat, diet, IUCN status, describer
- Wikipedia: Longhorn cowfish en.wikipedia.orgused for other names, colour, horns, sounds, swimming, naming history
- Saltwaterfish.com: Longhorn Cowfish saltwaterfish.comused for aquarium care, tank size, water parameters, temperament, diet, lifespan
Checked 2026-09-30. Text is written in our own words from these sources.