The magic of mushrooms: psilocybin influences behavior in the mangrove rivulus fish, Kryptolebias marmoratus.
Frontiers in behavioral neuroscience January 1, 2026 Dayna Forsyth, Nicoletta Faraone, Simon G. Lamarre et al.
Psilocybin reduces aggression and activity in mangrove rivulus fish, an emerging model for studying psychoactive compounds. Waterborne psilocybin treatment significantly decreased activity levels and the frequency of swimming bursts, an aggressive behavior, toward a conspecific fish from a different lineage, with modest effects on other behaviors. Considerable intraspecific variation in behavioral response occurred among these homozygous fish, suggesting the effects were largely independent of genotype. The findings add to evidence supporting psilocybin's potential as a therapeutic agent.