Catching several fish, hook or trap or spear...

Is there a test to check if this, that or the other species is 'not edible/poisonous' ? Is it the same story as mushrooms, relying on someone else experience/knowledge ?

Is there a 'poison tell tale" test ? If a laboratory test is the way, what does the test looks for ?

-Move to another section if deserved-

AFAIK there are few fish species that are poisonous and you can learn them in a few minutes since fish are generally pretty easy to tell apart. Like mushrooms, however, If there is any doubt don't eat it. If I am gathering mushrooms and don't know what one is, I will taste a very small piece. If it doesn't taste good I spit it out, if it does I might eat it on the spot. Even Amanitas won't kill you unless you eat a pretty big one or several, you just might wish you were dead for a while until the sick stomach and hallucinogenic poison wears off.

22 hours ago, npts2020 said:

Even Amanitas won't kill you unless you eat a pretty big one or several, you just might wish you were dead for a while until the sick stomach and hallucinogenic poison wears off.

Not all Amanita mushrooms are hallucinogenic. Amanita phalloides (death cap) contain toxins that inhibit RNA polymerase II, and is the most poisonous of all known mushrooms. It is estimated that as little as half a mushroom contains enough toxin to kill an adult human. Based on the chemical structure of some of these toxins, I suspect that the mushrooms would not taste bitter (unlike those containing alkaloids), so a taste test would not be advisable if death cap or similar mushrooms are a possibility.

When it comes to fish, there probably isn't a simple “edible or not” test like that. With Ciguatera, you apparently can’t tell anything by looking at the fish. It can look completely normal yet still contain the toxin. Pufferfish containing tetrodotoxin would be a whole other topic. I’d rather make sure that I know the species for certain and check for any local warnings. I certainly wouldn't taste anything to find out.

I see this sort of thing as a kind of Darwinian intelligence test.

We could quite reasonably view every occurrence of the words "edible", "inedible", "poisonous" etc. in non-fiction literature as a little gravestone commemorating the nameless and countless thousands who gave their lives in long past trial and error experiments to establish this knowledge.

Those cultures with an inbuilt distrust of "book larnin" may be doomed to repeat those experiments and have themselves removed from the gene pool in true Darwinian fashion.

2 hours ago, KJW said:

Not all Amanita mushrooms are hallucinogenic. Amanita phalloides (death cap) contain toxins that inhibit RNA polymerase II, and is the most poisonous of all known mushrooms. It is estimated that as little as half a mushroom contains enough toxin to kill an adult human. Based on the chemical structure of some of these toxins, I suspect that the mushrooms would not taste bitter (unlike those containing alkaloids), so a taste test would not be advisable if death cap or similar mushrooms are a possibility.

Half an amanita phalloides (the most deadly poisonous species of mushroom) is a pretty substantial amount to ingest. A small one will measure 5 or 6 cm across the cap and I have seen ones approaching 20 cm. While it doesn't taste bitter, I can't imagine many people liking the taste enough to mistake it for other mushrooms that are edible. BTW, I don't recommend tasting fish to see if it's poisonous, they are much easier to tell apart than fungi.

On 8/14/2026 at 5:05 AM, aliceinwonderland said:

Ciguatera

It should be noted with regards to ciguatera that it's not the fish itself that is poisonous, but rather the toxins that the fish have ingested. Thus, it is not a matter of identifying fish species, although some species are more likely than others to contain ciguatoxins.

According to Wikipedia:

Maitotoxin (MTX) is an extremely potent toxin produced by Gambierdiscus toxicus, a dinoflagellate species. Maitotoxin is so potent that it has been demonstrated that an intraperitoneal injection of 130 ng/kg was lethal in mice. Maitotoxin was named from the ciguateric fish Ctenochaetus striatus—called "maito" in Tahiti—from which maitotoxin was isolated for the first time. It was later shown that maitotoxin is actually produced by the dinoflagellate Gambierdiscus toxicus.

The chemical structure of maitotoxin is believed to be: