While there may be about 120 species of puffer fish, they all share the ability for which they’re named: when threatened, they can rapidly fill their bellies with air or water, expanding like balloons to twice or even three times their normal size! Another thing this species has in common? They all live in tropical waters—there are no known species of cold-water puffers. On an ominous note, puffer fish are the second most poisonous vertebrate, right behind poison dart frogs, to humans—thanks to concentrations of a toxic chemical, tetrodotoxin, in their skin and liver. Here’s one thing all puffers don’t have in common: they don’t all live in saltwater. There are 29 known species of freshwater puffers! Keep reading to learn about the puffers on exhibit at the Seattle Aquarium.
Nocturnal and solitary, this large puffer can be aggressive about protecting its territory from intruders. Its diet includes a wide variety of invertebrates like crabs, mollusks, corals, coralline algae, tunicates, sea stars and urchins.
Growing to one foot in length, this diurnal (active during the day) fish shares many features with other puffers. It has no lower rib bones or pectoral fins, allowing it to rapidly swallow large amounts of water or air to fend off predators. Although not visible, sharp spines reside under the fish’s skin and can pierce predators when the body is inflated.
This tiny puffer grows to five inches and is only found around the Hawaiian Islands. As with all puffers, this fish’s teeth grow throughout their lives and need to be continuously worn down through chewing on live rock or shells. In fact, members of the puffer family, Tetraodontidae, are named for their four large teeth, fused into a beak.
Also known as the spotted porcupinefish or just the porcupinefish, this puffer is found in tropical waters worldwide. Its body is covered in numerous long, sharp spines. When the fish’s body is not inflated, these spines can be seen lying flat and pointing toward the tail. However when the puffer puffs up, the spines point outwards, providing a formidable defense.