Longhorn Cowfish (Lactoria Cornuta)

Species Name : Lactoria Cornuta 

Care Level : Expert Only

Temperament : Peaceful

Color : White, Yellow

Diet : Omnivore

Reef Compatible : With Caution

Water Conditions : sg 1.020-1.025, 72-78° F, dKH 8-12, pH 8.1-8.4

Max. Size : 1' 8"

Origin : Indo-Pacific

Family : Ostraciidae

Minimum Tank Size : 200 gallons

The Longhorn Cowfish (Lactoria Cornuta), also called the Horned Boxfish, is a species of boxfish from the family Ostraciidae, recognizable by its long horns that protrude from the front of its head, rather like those of a cow or bull. They are inhabitants of the Indo-Pacific region and can grow up to 18 inches in length. This species of cowfish is the most well-known cowfish species in the aquarium trade.

The Longhorn Cowfish, also called the horned boxfish, is recognizable by the long horns that protrude from its head and its yellow coloring. The horns of the boxfish can be used to ward off predators through charging at the predator. If damaged, the horns can regrow within a few months. The main coloring of a longhorn cowfish is tan to yellow with blue and white polka dots. They may also have a dark brown to black circling around their mouth and eyes. Patches of brown are occasionally found on the body too. Females generally are larger than males.

Similar to other boxfish, the Cowfish Longhorn's skin is poisonous and, when threatened, it will release a toxin lethal to other tank members, including other Longhorns.

They should be kept in a tank of at least 200 gallons with a sandy substrate and plenty of live rock and natural algae. They are slow swimmers and should be given a low water flow. 

When possible, the Longhorn Cowfish should be the first fish introduced in the tank. It is intolerant of other Longhorns, so keep it in a large tank, with some live rock for algae scraping. Use caution if placing the Cowfish Longhorn in a reef tank as it may nibble on tubeworms. When housed correctly, the Cowfish Longhorn is long-lived.

This fish displays a unique behavior of blowing into the sand of the ocean floor to uncover buried food items, such as small worms. They are slow eaters, and should not be housed with aggressive eaters. Since they are omnivores, the Longhorn Cowfish should be offered a variety of meaty and vegetable foods. They are not picky eaters and will quickly become adapted to a variety of prepared aquarium foods and an occasional algae wafer and herbivore preparations.