Longhorn cowfish are tropical fish in the boxfish family, closely related to pufferfish. Like boxfish, they have a rigid, boxy frame that gives them their unique appearance. Because their rigid frame prevents them from generating thrust by making a wave with their body, they oscillate their tail fin rapidly to swim — a technique called ostraciiform swimming.

The cowfish (genus Lactoria) get their name from the long, horn-like spines on top of their head — and they’ll even charge like a bull if they feel threatened! There are other species of cowfish with shorter horns — so these ones get the “longhorn” moniker! The horns will grow back later if they are damaged.

In addition to the horns, the cowfish has another defense mechanism — it can exude a poison known as pahutoxin that is similar to sea cucumber toxins.

You can find this species in the Tropics gallery.