Pufferfishes and porcupinefishes are members of two closely related families—the Tetraodontidae and the Diodontidae—that are known throughout the world. But not always for the same reason.
One of those reasons is because in some cultures they are highly prized for food. The only trouble is that the members of these two families contain one of the most deadly toxins around. The poison is largely confined to the visera, gonads and skin, and thus when properly prepared, these fishes can be safely consumed. Usually.
But for most people, these fishes’ fame lies simply in their odd shape. When going about their normal day-to-day affairs of life, these fishes are sort of silly looking, all roly-poly, without a full count of the fins most fishes have. Plus, they have proportionally big, doe-like eyes, and just a few, very strong teeth. These teeth are essentially beaks, so strong that these fishes can break off bits of coral and even crack open the hardest of mollusk shells.
For the most part, pufferfishes and porcupinefishes keep themselves secluded, below rocky ledges or in deep shadows.
These are the pufferfishes and porcupinefishes that most divers know. Although typically seen in tropical seas, these two families have representatives that inhabit temperate waters.
Or at least some them stray into colder areas. This is the case of the five species that have been recorded off of California. The most pelagic of these, the Oceanic Pufferfish (Lagocephalus lagocephalus), has made it at least as far north as Mendocino County. The farthest the Pacific Burrfish (Chilomycterus affinis) has gotten seems to be San Pedro, while the Spotted Porcupinefish (Diodon hystrix), the Bullseye Pufferfish (Sphoeroides annulatus), and the Balloonfish (Diodon holocanthus) evidently have not gone much beyond San Diego. All of these, however, are well represented “south of the border”, ranging all the way into South America. There they are also joined by other worldwide species, such as the Guineafowl Puffer (Arothron meleagris).
Pufferfishes and porcupinefishes are slow and clumsy swimmers, (even though this fact is a bit demeaning to any diver who has tried to chase after one and found that it can still go a whole lot faster than any person can.) Supposedly as a means of compensating for this slowness, pufferfishes and porcupinefishes utilize another method of protection. When molested, they will fill themselves up with a large volume of water (or if out of the water, with air), and they become big balls of spines.
This defense technique has made these fishes famous among even non-divers. What cartoon about the sea can resist having one of these curious critters “set-off” and blow itself up like an underwater balloon?
And unfortunately, this same defense technique has very often backfired for the fishes. In some areas, they have been harvested and, in their inflated state, dried. The skins are thus cleaned out of all flesh and used as lampshades and other curios that are sold in knickknack stores around the world.
So for these individual fishes, it may be true that they have become nothing more than a lot of “hot air.” They are really fascinating creatures, with many, many unique characteristics and habits. Why, at the very least, when found in their typical habitat, these tend to fill with “warm water” not just “hot air.”