Stranger danger? Then take a tip from the Cowfish! They can exude poison from their skin if threatened, which repels not only enemies but also its own kind.
The Longhorn Cowfish is so named because of the protruding horns on its head that resemble those on a cow or bull. It’s one of approximately 20 tropical species in the Boxfish family, whose notable adaptation is the fusion of the fish’s scales into a solid, box-like carapace from which the fins and tail protrude. The Longhorn Cowfish lives in shallow coral reef lagoons, seagrass beds and muck zones across the Indo-Pacific. It grows up to 50 cms (20in) in length and is solitary and territorial. Its skin is poisonous, and when the fish is threatened it will exude a deadly toxin called Ostracitoxin which repels predators and is also toxic to other Cowfish. The Cowfish is omnivorous, feeding on minute algae, sponges, polychete worms and small crustacea and fish which the Cowfish unearths by blowing jets of water into the sand. Because of its unusual shape and colour the Cowfish is prized by the aquarium trade. It’s easily caught by hand, and makes a grunting noise when captured.