If you've ever wondered why dolphins always appear to have permanent euphoric smiles stretched across their faces, this could offer an explanation: BBC filmmakers recently caught wild dolphins on camera getting high by chewing on a toxic pufferfish, reports Discover.

Each member of the pod of cetacean stoners appeared to gently pass the fish around after each hit, forever redefining the notion of a "puff pass."

The discovery that wild animals purposely get intoxicated is nothing new. Researchers have long been aware of drunk monkeys, hallucinating porcupines, and magic mushroom-eating reindeer, for instance. But this is the first time such behavior has been directly recorded in marine mammals.

"After chewing the puffer and gently passing it round, they began acting most peculiarly, hanging around with their noses at the surface as if fascinated by their own reflection," said Rob Pilley, one of the producers of the documentary. "This was a case of young dolphins purposefully experimenting with something we know to be intoxicating."

The event was filmed in waters near Mozambique on the southeast coast of Africa. Apparently the dolphins were observed playing with pufferfish for up to half an hour, frequently nudging the fish with their rostrums.

"We saw the dolphins handle the puffers with kid gloves, very gently and delicately like they were almost milking them to not upset the fish too much or kill it," explained Pilley.

Pufferfish are best known for their ability to inflate their bodies when threatened. But when that doesn't seem to work, they also have the ability to secrete tetrodotoxin, which can be a deadly poison in the certain doses. In low doses, however, it can cause numbness, tingling and slight lightheadedness. Interestingly, this effect can be mildly felt by humans who handle raw pufferfish flesh to prepare it for consumption.

For the dolphins to play around with a tetrodotoxin-secreting pufferfish, it demonstrates that they are experienced at handling the animals. Tetrodotoxin is not a poison you want to mess around with, as people are known to get seriously poisoned by it every year. The drug has the potential to slow heart rate to dangerous levels, lower blood pressure and cause respiratory distress, which could lead to paralysis or death. Tetrodotoxin is 120,000 times as deadly as cocaine, 40,000 times as deadly as meth, and more than 50 million times as deadly as marijuana. It's actually one of the most toxic compounds known to man. So licking a pufferfish is not a recommended way for anyone to get a buzz on.

Scientists are unsure about how common this behavior is among dolphins, but it's certainly an interesting finding. Stoned dolphins — who would have guessed? It just goes to show that drug use may not be such aberrant behavior in nature after all.

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