Had my doubts but this from Wikipedia
Sarpa salpa became widely known for its ichthyoallyeinotoxic effects following widely publicized articles in 2006, when two men ingested it at a Mediterranean restaurant and began to experience many auditory and visual hallucinogenic effects.[5] These hallucinations, described as frightening, were reported to have occurred two hours after the fish was ingested and had a total duration of 36 hours.[6]
The fish, and especially its viscera, have been assessed as potentially unsafe by a study conducted on Mediterranean specimens.[7] It is believed that the fish ingests a particular algae or phytoplankton which renders it ichthyoallyeinotoxic.