The longhorn cowfish, also called the horned boxfish, is recognizable by the long horns that protrude from its head and its yellow coloring. These horns may have evolved as an adaptation that makes the fish appear difficult to swallow for most predators. If damaged, the horns can regrow within a few months. Cowfish can range in size from about 4 inches to over 40 inches long.
Range & Habitat
Primarily coral reefs in lagoons, on reef flats, and on protected seaward reefs, all throughout the Indo-Pacific.
Conservation Status: Not Evaluated
Longhorn cowfish are omnivores—they feed on benthic algae, various microorganisms, foraminiferans, sponges, polychaete worms, mollusks, small crustaceans and even small fish.
Fun Facts about the Longhorn Cowfish
- Adult longhorn cowfish are often solitary and territorial.
- They are able to locate and feed on marine invertebrates by blowing jets of water into the sand.
- Longhorn cowfish are very poisonous—if severely stressed, they can exude the toxin ostracitoxin, which is unique among known fish poisons.
- Their unique method of swimming, called ostraciform swimming, causes them to look as if they’re hovering.
“Longhorn Cowfishes .” MarineBio Conservation Society, 22 Dec. 2020, marinebio.org/species/longhorn-cowfishes/lactoria-cornuta/.
National Aquarium: Longhorn Cowfish, https://aqua.org/explore/animals/longhorn-cowfish