Pufferfish vs. Blowfish: Are They the Same Thing?


Written by Rebecca Mathews

Updated: August 30, 2023

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Experts estimate the total number of living fish species on the planet sits between 32-34,000. That’s more than mammals, birds, reptiles, and amphibians added together, so it’s no wonder some species look similar and we get confused. For example, pufferfish vs. blowfish: are they the same thing? If not, why not? Read on to discover the similarities and differences between these fish.

Are Pufferfish and Blowfish the Same Thing?

Scientifically, pufferfish and blowfish are not the same things, but people often use the names blowfish and pufferfish to describe any fish that inflates itself with water as a defense mechanism.

This creates some confusion, so people tend to differentiate fish that puff up by describing them as smooth or spiny pufferfish. This is not scientifically correct.

Porcupine Pufferfish



pufferfish in the open water in Bonaire.

©J.T. Lewis/Shutterstock.com

Pufferfish vs. Blowfish: Classification

Both blowfish and pufferfish sit in the order of Tetraodontiformes. This order has ten families with over 360 species. Smooth-skinned pufferfish are part of the Tetraodontidae family, whereas spiny blowfish are part of the Diodontidae family.

Pufferfish vs. Blowfish: Appearance

Calm Tetraodontidae-family pufferfish have thin bodies with round eyes set in a large bulbous head. Small fins protrude from their smooth sides, and they eat with a sharp beak made from fused teeth. When danger approaches, a pufferfish draws in water to inflate its body into an inedible ball. This is for protection against predators.

Many species of pufferfish exist, such as pygmy pufferfish and Chinese puffers. They all look a bit different but have the same puffing-up capability.

Diodontidae family blowfish, often called porcupine fish or balloonfish, also puff themselves up with water. The main difference is their spiny skin, hence the name porcupine fish. Their spines are non-venomous and modified scales. Pufferfish don’t have spines, but some species have rough, bumpy skin.

Blowfish species are generally larger than pufferfish. Long-spine porcupine fish can reach up to 20 inches long. Another difference between the two fish species is the mouth area. Pufferfish develop a tough, pointed beak, whereas blowfish develop hard bite plates situated on their upper and lower jaw.


The stomach of a pufferfish can inflate up to three times its normal size.

©Moize nicolas/Shutterstock.com

Why Do Pufferfish Blow Up?

Pufferfish and blowfish have stiff bodies, so they are not adept swimmers that dart around to avoid predators, and they are solitary fish, too, so there’s no safety in numbers.

To fend off predators, they both rapidly intake water to inflate or ‘puff up.’ By making their bodies larger, they deter predators from taking a bite. Imagine your burger suddenly inflating to two or three times the size so you couldn’t fit it in your mouth. It’s a sudden shock that’s off-putting and an excellent defense mechanism.

But puffer and blowfish have another defense trick. Predators that still take a bite receive a mouthful of tetrodotoxin. It’s a poison in their skin and organs that not only tastes bad but it’s also more powerful than cyanide. One bite into a blowfish or pufferfish is enough to kill small predators and make larger ones unwell.

Pufferfish vs. Blowfish: Predators

Other than humans, pufferfish have very few predators due to their sudden inflation skills and toxic venom. However, sharks, especially tiger sharks, can eat an inflated blowfish or pufferfish whole, so the bad taste does not affect them. Immune to their toxins, sharks don’t suffer from tetrodotoxin poisoning.

Sea snakes are immune to their toxins as well, but they find it more difficult to swallow a whole inflated puffer or blowfish. Sea snakes chiefly prey on juvenile puffers.

Tiger Shark (Galeocerdo Cuvier) - swimming in ocean

Sharks, especially tiger sharks, can eat an inflated blowfish or pufferfish whole, so the bad taste does not affect them.


Pufferfish vs. Blowfish: Diet

Both blowfish and pufferfish species prefer to eat at night; they have eyes that “sparkle” to help them see in the dark water.

Their diet is very similar. They tend to eat mollusks, sea urchins, hermit crabs, starfish, worms, and snails, utilizing their sharp beaks or hardened jaw plates to crack open a meal. Both fish also eat algae, plant matter, and any pieces of detritus, such as wayward fish meat left over from other predators’ meals.  

Pufferfish and blowfish can’t digest food in their stomach. It’s because they use their water-absorbing stomachs to inflate their size and scare off predators. Instead, they digest food in their intestines.

Pufferfish vs. Blowfish: Habitat

Pufferfish and blowfish live in very similar habitats.

They are located in tropical or subtropical waters, including the Caribbean, Indo-Pacific region, Australia, Japan, southern California, Colombia, Canada, and Brazil.

Both fish prefer sheltered areas such as coral reefs, ledges, caves, and underwater seaweed or grass beds. Although juveniles and the majority of adults prefer shallow water, they’re spotted in water up to 656 feet deep, too. Pufferfish and blowfish are common sights on tropical diving tours. They’re usually friendly enough to stick around when divers appear.

Another popular habitat for pufferfish and blowfish is aquariums. Bloat from Finding Nemo is a spiny blowfish kept in the dentist’s aquarium.

And speaking of aquariums…

Can Pufferfish and Blowfish Be Kept in the Same Tank?

Experts say both pufferfish and blowfish are incredible aquarium fish. However, they’re not for beginners because they have specific dietary requirements and a lot of waste output, increasing their care needs over easy fish like guppies. Spiny blowfish can grow large, too, so they need at least a 200-gallon tank. Beginner-size tanks aren’t suitable for any type of inflating fish.

Puffers and blowfish are both aquarium-friendly, but they are solitary fish. Mixing species or even more than two of the same species in a small environment isn’t a good practice because it leads to food competition or fighting. Another point to note is their diet. Puffers and blowfish eat meat, so if you already have invertebrates or small fish, a puffer species may eat them. In the case of small fish, puffers nibble on their fins and tails.

Are Pufferfish and Blowfish Dangerous?

Pufferfish and blowfish contain toxic venom that’s dangerous to predators, but they’re not aggressive toward humans. Blowfish and pufferfish prefer to paddle about the coral reef using their short fins and great eyesight to hunt out shellfish. Divers should not touch any species of blow or pufferfish because their toxins can transfer through the skin.

Their venom is created from their diet. Puffers and blowfish synthesize toxins from their prey’s bacteria, turning them into self-defense venom. However, in some parts of the world, such as Japan, Tahiti, and Hawaii, pufferfish and blowfish are a tasty delicacy. In Japan, pufferfish meat is called fugu. Chefs undergo a 2-3 year apprenticeship to avoid poisoning customers.

Due to overfishing, the IUCN listed the Chinese puffer (Takifugu chinensi) as critically endangered in 2011.

Pufferfish Meat

In Japan, pufferfish meat is called


. Chefs undergo a 2-3 year apprenticeship to avoid poisoning customers.

©funny face/Shutterstock.com

Are Blowfish and Pufferfish the Same Thing?

Blowfish and pufferfish are not the same thing. Although they belong to the same order, their classification is:

  • Pufferfish: Tetraodontidae (smooth or bumpy skin)
  • Blowfish: Diodontidae (spiny)

However, blowfish and pufferfish are terms used interchangeably to describe the whole genus of fish that inflate with water. This is confusing, especially when aquariums list all fish in the Tetraodontiformes order as pufferfish.

Even though pufferfish and blowfish are commonly known as the same thing, they are two different fish species.

The Main Differences: Quick Reference Table

Smooth or bumpy skinErect spine or spiny when inflated
One inch to two feetOne inch to two feet
Lives in coral reefs, ledges, caves, seaweed, and seagrass bedsLives in coral reefs, ledges, caves, seaweed, and seagrass beds
Contains tetrodotoxinContains tetrodotoxin
Eats mollusks, shrimp, shellfish, sea urchins, hermit crabs, algaeEats mollusks, shrimp, shellfish, sea urchins, hermit crabs, algae
Bony beak formed from fused teethHardened plates on the upper and lower jaw
Eaten as a delicacy in JapanEaten as a delicacy in Japan, Hawaii, the Philippines, and Tahiti
Suitable for experienced fish keepersSuitable for experienced fish keepers

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About the Author

Rebecca is a writer at A-Z Animals where her primary focus is on plants and geography. Rebecca has been writing and researching the environment for over 10 years and holds a Master’s Degree from Reading University in Archaeology, which she earned in 2005. A resident of England’s south coast, Rebecca enjoys rehabilitating injured wildlife and visiting Greek islands to support the stray cat population.

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