Scientists in Lebanon fed tilapia pellets laced with cannabis oil to see if cannabinoids would have a calming effect on fish. Their conclusion: Unlike other pets such as dogs and cats, fish feel no such high on THC. So all you stoners with fish tanks: you can stop trying to give your fish contact highs.
It wasn’t that fish didn’t show any effects to THC; they just weren’t the desired or hypothesized effects. Quite the opposite, actually. Cannabis not only did not improve the fishes’ immune response, but those fed cannabis-laced foods developed slightly higher metabolisms, which consequently reduced their growth rate.
This experiment wasn’t really done to answer the late-night musings of reefers but rather to see if cannabis could relax aquacultured fish who are raised in cramped, hectic environments. The hope was to create healthier/happier fish, which could ultimately produce better yields. Sadly, the answer appears to be no.
The paper is published in the scientific journal, Aquaculture Research.