Longhorn Cowfish (Lactoria cornuta)

The Longhorn Cowfish inhabit the reefs of the Indo-Pacific, usually in the less turbid waters. The body is tan to yellow and covered with white and blue 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 Longhorn Cowfish tends to be dramatically smaller – 16″ or less.

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.

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.