My buddy in Colorado is new to fishing and caught this thinking it was a smallmouth bass. All I know is it most definitely is not, as I've caught hundreds if not thousands of smallmouths and this is not it. To me it looks like a shad, although I've never seen or caught a shad either. Never seen or caught whatever this fish is... Anyone know? He caught it out of Windsor Lake in Colorado and I looked online that Windsor has perch, channel cats, trout and bluegill. And it's definitely not any of those either...

Kind of resembles a Gizzard shad

Yeah it looks shadd-ish to me but I've only seen pics of shad. I told him I'd ask on here.

It looks like a species of whitefish to me. I don't know enough about the specific species of whitefish in Idaho to say which one.

Keith

This was in Colorado not Idaho but you could be on to something with whitefish. I've caught a few but they didn't look like that too much

If you have Gizzard shad in Colorado that is what it looks like. Wish I could see the dorsal fin and head/mouth more to be sure. Its not a Whitefish since there isn't an adipose fin.

how long is it

Mountain Whitefish

agree...

The anal fin on the pictured fish appears to be too long to be a mountain whitefish. I think it is a gizzard shad.

Mountain whitefish- http://www.roughfish.com/mountain-whitefish

Gizzard shad- https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=492

I don't know what kind of shad it is, but it looks like some kind of shad. It's got the correct fin shape and design for a shad. It's got the wrong fins for it to me a mountian whitefish. Also I have never seen a mountian whitefish be that fat.

Fur and Feather, as well as LAtrapper, pointed out the two reasons that can't be a whitefish of any specie. The pictured fish has a long narrow anal fin and no adipose fin(or any dorsal fin just ahead of the caudal fin)......like a shad.

Dace

pig castrator.

We catch them here and that is what we call them, whitefish, rocky mountain. What ever.....

It looks a lot like the lake whitefish we have in Minnesota. The small hooked under mouth and silvery color has to be a species of whitefish.

Definitely not a whitefish. I've caught and eaten tons of them in Montana and Wyoming.

I've caught lots of shad in CA and some in NY state and here in France, but this fish looks more to me like a member of the minnow family. The curve on the rear edge of the tail and mouth shape are the best clues. The minnow family is large and includes carp, but this almost looks like a well fed shiner of some sort. Nessmuck was probably onto something. When you put a moving water fish like a lot of those in the minnow family and put them in a reservoir with lots of food and no current they can get a body shape that doesn't jive with what the books say.

Pete

Goldeneye?

Well I think you guys are onto something with shad. Swift4me, you may be onto something as well but I don't really know. I just know the fish that I'm familiar with. My buddy and I went out on the lake today and caught between 15 and 20 smallmouth apiece (between 10" and 15"), plus a couple bonus crappie 11" and 13"