Since late 2013, outlets as serious as Smithsonian Magazine have circulated the claim that dolphins intentionally get "high" by harassing pufferfish. It is further claimed that this is a collective behavior in which dolphins pass around the fish to share among their pod. The claim continues to circulate on social media in the form of image memes like this one:
In an extraordinary scene filmed for a new TV series, the dolphins are shown gently passing the fish between them. Experts believe the creatures are using the toxins, which emerge from the puffer fish as part of its defence mechanism, for their own enjoyment.
They nudge the fish with their snouts and as the toxin is released into the water, they seem to lapse into a trance-like state.
At one point the dolphins are seen floating just underneath the water's surface, apparently mesmerised by their own reflections.
The dolphins were filmed gently playing with the puffer, passing it between each other for 20 to 30 minutes at a time, unlike the fish they had caught as prey which were swiftly torn apart.
Tetrodotoxin simply doesn’t make sense as a drug[...] In very, very, very low doses, tetrodotoxin causes numbness, tingling, and the slight lightheadedness that fugu, the Japanese preparation of raw pufferfish flesh, is known for. I guess it’s possible to see how one might relate these mild effects to the “high” feeling that comes from THC, the main ingredient in marijuana, but it’s a stretch to say the least. [...]
I find it tough to believe that dolphins are so careful that they can walk the fine line between tingly lips and maddening paralysis, especially when different individuals of the same species of pufferfish can carry vastly different amounts of toxin in their tissues. Instead, what I hear in the BBC’s description is naive animals learning a hard lesson: soon after ‘puffing’ on puffer, young male dolphins were filmed behaving strangely, even near-motionless at the surface. It doesn’t sound like a happy high; it sounds like the first stages of tetrodotoxin-induced paralysis, with the dolphins instinctively (and perhaps luckily) hovering in shallow water to retain the ability to breathe. It seems unlikely that they interact with puffers like this routinely.
I find Christie Wilcox's interpretation pretty convincing on its own, but I wonder if any other experts have weighed in on this or if any new observations have been made since 2013?