Hi All,

I've got a creek behind my house with loads of these minnows. Anyone know what they might be?

Let's get a bump here.

I'm no pro at this but I did pull up a minnow identification page...

FHM

Was the closest thing I saw. Lateral Line, Eye / Mouth location, Tail, and fins seem to match up (at least they do to rookie me).

Is there a prize if I get it right?

+1

I am not sure those are fathead minnows. For one item FHM never have a dark spot on the caudal peduncle. From the poor quality pictures to me they look to have more body features of a California roach Hesperoleucus symmetricus. There are some varieties of the species that qualify them as official varieties or subspecies of the species. Better close up pictures with good images of the head shape and good side body views will help with a more positive ID.

I won't second guess here, but (to me) eyes are shiner-like, as are dorsal fin. I'm relatively sure they are not FHM.
dorsal is too high and too flat (straight) on the aft side.

Thanks for looking, all. I’ll grab some better photos and repost. I initially though fhm, too, but that’d be weird since this is a pretty remote small creek in Ca and they aren’t native.

Dylan,

FHM are naturalized in CA in some locations. Although the map below probably doesn't document all of the locations, they are definitely occurring in areas intersecting the Sacramento River watershed. You can look at map where documented in the link below.

https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=621

I'm with snipe for identification of your minnows. I still think your minnows look more like California Roach than FHM. Notice in your pics the minnows have the lateral dark stripe similar to CA roach. Same as snipe says - Dorsal fin of your unknown minnows is not the correct shape for FHM although FHM are introduced and expanding their range in CA. Plus the unknown minnows do NOT have the 2nd short rudimentary dorsal fin ray thickened & separated from the 1st dorsal ray by a membrane as do FHM. Try to get some good close up clear body profile images. A good close-up head profile of the head will verify ya or nay for FHM. Again the side body spot at the back of the caudal peduncle says no for FHM.

For good identification we need better pics than these pics of the CA Roach.
https://www.inaturalist.org/taxa/67610-Hesperoleucus-symmetricus/browse_photos

Ahh, see what you guys are saying about the aft of the dorsal fin. If it is California Roach, that would not be a bad thing. Seem to be tough and do well under stressful conditions. These would probably reproduce well in ponds? Best part is that Dylan could always get more from the creek.