With toxins in their bodies and the ability to inflate like a balloon, pufferfish can intimidate many of their enemies. However, in Japan, they are caught and prepared as a delicacy known as fugu.
If you’ve ever heard of pufferfish, you surely know that they can expand their bodies like a balloon. These fish can triple their waist size. If humans could do this, imagine inhaling air into your belly to stretch your waist to 3 meters, then floating around the room, continuously hitting the ceiling.
This is what a pufferfish will do when threatened. This defensive strategy makes pufferfish look intimidating. Some species even have spines around them, turning them into a spiky ball that can threaten any fish that might consider eating them.
But how exactly do pufferfish inflate? Do they ever float away and drown upside down?
Pufferfish do not inflate their lungs but drink water into their stomach.
In reality, when you see a pufferfish inflating, they are not pumping air into their lungs. Instead, pufferfish drink large amounts of water into their stomach. These massive gulps, usually between 10-15, are pumped in through a special muscle in their mouth.
After that, the pufferfish’s special stomach begins to expand. Under normal circumstances, the stomach of a pufferfish has folds similar to an accordion. This allows it to stretch up to three times its normal size. And when filled with water, the pressure does not cause the pufferfish’s stomach to burst.
Pufferfish have muscles in their esophagus that act as a valve to keep the water in. Once their stomach is fully inflated, the esophageal muscles tighten, preventing the fish from deflating. It is only when the danger has passed that the pufferfish uses another set of muscles at the base of its abdomen to expel the water.
These are muscle sets that most other fish do not possess. Only pufferfish, having evolved this ballooning ability, can do so. The ancestors of pufferfish lacked ribs and pelvic bones. If they had these two types of bones, they would not be able to inflate.
In addition to bones, pufferfish also had to sacrifice their stomach’s ability to digest food. For pufferfish, their stomach is only used to hold water, not to contract for digesting food. Therefore, their intestines must work harder to take on the entire digestive task.
In return, the ability to inflate like a balloon provides pufferfish with an effective defensive strategy. Very few underwater creatures are interested in a floating spiky ball. And even if a pufferfish is suddenly attacked from above by a bird of prey, they can escape thanks to this mechanism.
Unlike underwater, pufferfish lifted into the air can still gulp air to inflate their stomach. At this moment, they truly become a balloon. When a bird catches an inflated pufferfish in its beak, it tends to spit the fish out because it cannot swallow it.
In a study, scientists observed that up to half of the pufferfish could escape a bird’s beak by using their inflation strategy. And even if they cannot escape, pufferfish have a mutually harmful strategy against any enemy that dares to swallow them.
A pufferfish inflating when caught by a bird of prey. The bird is ready to release its prey because it knows it cannot swallow it.
This is because the body of a pufferfish is coated with a neurotoxin called tetrodotoxin. It is 1,200 times more toxic than cyanide. So toxic that a single pufferfish can kill 30 adult humans.
Tetrodotoxin from pufferfish numbs the tongue and lips, causes dizziness and vomiting, followed by numbness and tingling throughout the body. It will make your heart race, but blood pressure drops, ultimately leading to complete paralysis. When your diaphragm can no longer contract, you essentially stop breathing and die.
The origin of tetrodotoxin in pufferfish is still a topic of debate, but most scientists believe it is produced by bacteria living in their intestines.
Pufferfish store tetrodotoxin in their skin, intestines, and especially in their ovaries and liver. However, if prepared correctly, some skilled chefs can serve pufferfish in their restaurants.
The Japanese fugu dish made from pufferfish. The flesh of the pufferfish is not toxic, but chefs must be highly skilled when preparing pufferfish, as toxins can accidentally transfer from the fish’s organs to the flesh if not filtered carefully.
In Japan, pufferfish are often prepared as a delicacy known as fugu. In South Korea and China, people also commonly eat pufferfish. This is surprising because pufferfish, with its toxins, is ranked as the second most toxic vertebrate in the world.
So, to know how delicious their flesh must be, people are willing to risk their lives to eat it.
