The Fish Like a Spiked Ball

The puffer fish is named after its ability to inflate itself like a ball in danger or stress. They pump water into a sac-like enlargement of their stomach, causing them to deform into a ball. This change in volume makes it almost impossible for predatory fish to swallow the puffer fish and it can even suffocate them. If this stress reaction is caused willfully by divers, puffer fish can sometimes inadvertently suck in breathing gas from divers, which leads to them being buoyant and floating helplessly on the surface. This usually ends fatally for the animal. They are rarely eaten by predatory fish, but dolphins have been observed to get intoxicated on these animals by chewing lightly on them, which causes the puffer fish to release small doses of the strong neurotoxin tetrodotoxin. This poison is fatal to humans and no antidote is known; ironically, however, in Japan puffer fish is considered a delicacy called fugu. However, people’s curiosity about this questionable delicacy leads to accidents every year.