Cowfish Longhorn
![]() |
![]() |

The Cowfish Longhorn inhabit the reefs of the Indo-Pacific, usually in the less turbid waters. The body is yellow and covered with white dots, and is occasionally referred to as the Yellow Boxfish; however, the Longhorn is not to be confused with Ostracion cubicus, commonly called the Yellow or Polka Dot Boxfish. In the wild, it is not uncommon to see a 20" specimen, while in the aquarium the Cowfish Longhorn tends to be dramatically smaller - 16" or less.
When possible, the Cowfish Longhorn 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.
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.
Since they are omnivores, the Cowfish Longhorn should be offered a variety of meaty and vegetable foods. They are slow eaters, and should not be housed with aggressive eaters.
Quick Stats:
Minimum Tank Size: 125 gallons
Care Level: Difficult
Temperament: Peaceful
Reef Compatible: With Caution
Water Conditions: 72-78° F, sg 1.020-1.025, pH 8.1-8.4, dKH 8-12
Max. Size: 1' 8"
Color Form: White, Yellow
Venomous: Poisonous When Stressed or Dies
Diet: Omnivore
Origin: Indo-Pacific
Family: Ostraciidae

If you have experience with this profile, please leave your review. If you have questions regarding this profile, please ask questions on our forum.
![]() Xmas moss Aquarium Fish Tank 55 75 90 100 125 Gallon A1 $4.70 Time Remaining: 9d 13h 21m Buy It Now for only: $4.70 |
![]() 240 gallon glass fish tank and matching cabinet set $570.00 (9 Bids) Time Remaining: |