Fish can be tricky in the context of iNat, unless it is a very distinctive species or in a species poor region it may require better pictures compared to what you can get away with in for some other taxa. To me the first step in identifying fish is to have the best pictures you can get to start with (hard if they aren’t in hand). After that I’d always recommend trying to determine what family the fish belongs to first (or even order), then you have fewer genera to sort through.
Some my favorite web resources:
Fishes of Wisconsin (super detailed. best for WI, MN, MI, IA, IL, Ontario but worth a look in other places that have the a fair number of the same species):
https://search.library.wisc.edu/digital/AWFIWUVZSK4EFH9B
Similar to Fishes of WI but more abbreviated and with better pictures:
https://www.seagrant.wisc.edu/fish-id/
A couple of the better image resources on fish bones:
https://www.floridamuseum.ufl.edu/fishatlas/content/default.html
https://quod.lib.umich.edu/f/fish2ic?g=fish-ic;page=search
https://osteobase.mnhn.fr/squelette.php?lang=en&idStructure=1&idTaxon=25