All pufferfishes are small in size, and only some species can reach an impressive length of 1.2 m. They are typical inhabitants of coral reefs, but they are also found in freshwater rivers of South America and North Africa. The entire body of puffers is covered with small sharp needles. These fish spikes are used as a defensive shield.
Picking up a large amount of water, it swells, like a balloon, exposing its needles outside. The attacker can not grab the fish (try to catch the apple with an apple suspended on a rope) and leave it alone. If the predator is large enough to capture the bloated puffer-whipped whole, then both die. The attacker because he can not swallow a sharp ball – needles cling to the throat, and the victim, because he can not get out of the closed mouth.
Biologists believe that the ability to inflate the elastic stomach due to a large amount of water (or air) appeared in fish in the process of evolution. In themselves, these fish are very slow, and instead of escaping from the attacker, they have acquired sharp needles and the ability to several times increase in size. The shape of the ball turns the fish into an absolutely inedible bubble. And the poison that accumulates on the thorns is 1200 times stronger than cyanide. In one fish it contains so much that enough to kill 30 adults, and there is no known antidote in nature.