The members of the porcupinefish family have evolved an interesting means of defense. When threatened by a predator, they fill their bodies with water until they swell like a balloon. This makes them too large for the predator to swallow.
Porcupinefishes also have the added protection of a spiny covering on their body.
Pufferfishes comprise another group of inflatable fishes. The Sharpnosed puffer is one of the most beautiful of the puffer species. It is shown here in its natural state. Besides the beautiful colors and spots on this species, there is a large black spot near the animal's back fin. This resembles an eye and helps draw the attention of predators toward the fish's tail and away from the its head.