Fact: Sometimes porcupinefish and pufferfish are collectively known as pufferfish (this is where confusion often sets in)
The Tetradontiformes are represented by 10 families with about 360 different species overall; most are marine and they are most diverse in the tropics with very few species in temperate waters, they are completely absent from cold waters. A few species are found in freshwater streams and estuaries.
This post is mostly focused on the difference between porcupinefish and pufferfish because during a conversation with a friend today we were unsure whether the fish we were discussing were called porcupinefish, balloonfish or pufferfish. So this post is for my dear friend and big brother Kana :D
Porcupinefish / Balloonfish
Puff up body by drawing in water or air through the mouth into a small chamber near the stomach.