if you see the term F0 put next to a fish or in a descrption about a fish it means it was caught in the wild.
F1 means its the babies from the wild fish so is the F1 generation of the fish, meaning it was the first batch to be born and raised in an aquarium. F2 means third generation fish, second generation to be born in the home aquarium and so on and so forth.
Genrelly an F0 is the best fish to have
Hope this clears it up for you.
DD