5 facts about the Long Horned Cowfish

Long Horned Cowfish

By Frances Lam Li Min, diver at S.E.A. Aquarium and team
Photos by Boon Ping Ng, aquarist at S.E.A. Aquarium

Don’t be fooled by its pouty mouth and doe eyes. Behind its overwhelming cuteness lies a deadly truth: the Long Horned Cowfish releases a lethal toxin when under stress (such as when faced with potential predators). Here are five facts you probably don’t know about the Long Horned Cowfish:

1) It may kill itself too

cowfish featured

The Long Horned Cowfish excretes a neurotoxin called Ostracitoxin or Pahutoxin from the cells under its skin, otherwise known as “club cells”. This is lethal enough to kill other tank inhabitants, including itself.

2) Kaleidoscopic skin

Matrix of plate-like scales of the Long Horned Cowfish’s skin
Matrix of plate-like scales of the Long Horned Cowfish’s skin

Its unique plate-like scales are fused together to form a mesmerizing matrix that engulfs the box-like carapace. These intricate details cannot be seen with our naked eyes, but under the light, it gives off an amazing kaleidoscopic effect.

3) Eyes like the Milky Way

Look into my cosmic eyes
Look into my cosmic eyes

Their hypnotic sapphire eyes seem to have encapsulated the Milky Way, thanks to the presence of a special pigment called “corneal iridescence”. This is created by the layering of tissues which is Mother Nature’s way of blocking direct sunlight overhead, so as to facilitate its foraging in the shallow reefs.

4) Hovers like a spaceship

Despite being a fish, they don’t quite swim like one. Their unique method of swimming, called “ostraciform swimming”, causes them to look like a hovering spaceship.

5) They grunt

They are such slow swimmers that they are easily caught by hand and make a grunting noise when captured. Click the play button below to hear them grunt!


Come visit the adorable Long Horned Cowfish at the S.E.A. Aquarium and see if you can find them in one of our habitats. Hint: they are housed together with their relatives the boxfish and pufferfish.

Facebook Comments