I have a character who was blindfolded and fed fish. (just go with it). I want him to use the type of fish as a way to narrow down his location. Ideally, I'd like to place my story in the Great Lakes region of North America (write what you know!). Is there a kind of fish that would only be found in a great lake, not in a smaller lake or river? Would someone reasonably be able to identify this type of fish by taste? (If it matters, the story is currently set in late spring, but I could be flexible about that. Not winter, but any other time of year could work). Thanks for any help, fisherfolk!