In Arabic, it is known as “the fish that makes dreams.” This is no exaggeration. A single meal of salema porgy may contain a toxin that causes several days of vivid, sometimes frightening hallucinations, which scientists equate with the effects of taking LSD. 

The small, golden-striped sea bream lives off Africa’s East Coast and throughout the Mediterranean. Ancient Romans supposedly treated salema porgy like a recreational drug, while Polynesians employed its psychedelic powers during ceremonies. The effects can last for days and may include “demonic hallucinations.” A 2006 study that examined two cases of men who ate salema porgy on the French Riviera noted that one man had auditory hallucinations of “human screams and bird squealing,” while the other “was not able to drive anymore as he was seeing giant arthropods around his car.”

Scientists understand very little about the forces at work behind the fish’s hallucinogenic side effect, which is officially known as ichthyoallyeinotoxism. Perhaps it’s the result of something in the phytoplankton they eat. There might also be seasonal influences at play: The 2006 study reports that levels of the trip-inducing toxin are highest during autumn, but most poisonings happen in late spring and summer. Further complicating things is that most salema porgy aren’t hallucinogenic at all, and those that are lack uniform poison distribution. The head is a common psychedelic source, but some sections are toxin-free.

If you do find yourself experiencing intense fish-inspired nightmares, remember: It’s all your in head. But it was all in the salema porgy’s head first.