Thought this was going to be a long straight knife when I pulled it out of the mud, then saw the radius in it. Have always referred to it as my carp scraper.
Carp were not native to N. Amer until the 1800`s and your piece is probably several thousand years old but you`re right it would make a great scaler for any course scaled fish, maybe fresh water Drum or Bass, also could have been used to work wood. Interesting utilitarian tool. Nice find, makes one think.
I have found some "bent" scrapers and points and never really did come up with a good reason/purpose for them??
Ya, the carp around here came from the Chinese originally, I love catching them, they get huge, eat anything and fight hard...way more fun than the Harbor Freight crap the Chinese send now...