Day 28: Puffer Fish

There are more than 120 species of pufferfish worldwide. Most are found in tropical and subtropical ocean waters, but some species live in brackish and even fresh water. Almost all pufferfish contain tetrodotoxin, a substance that makes them foul tasting and often lethal to fish. To humans, tetrodotoxin is deadly, up to 1,200 times more poisonous than cyanide. There is enough toxin in one pufferfish to kill 30 adult men. Biologists think pufferfish developed their famous “inflatability” because their slow, somewhat clumsy swimming style makes them vulnerable to predators. Pufferfish use their highly elastic stomachs and the ability to quickly ingest huge amounts of water to turn themselves into a virtually inedible ball several times their normal size.