American Pike Minnow Infestation

[matt johnson]

Matt, thanks for the note. The fish I caught looked pretty much exactly like the the juvenile Sacramento Pikeminnow here (on the same UCD web site)

They really didn't look at all like the hardheads photos.

They could very well be small Sac Pikeminnow... Have to check that upper lip margin. Its the only sure diagnostic! I have sorted through hundreds of juvenile Hardhead/Pikeminnow back in my days working as a Fish Tech on rotary screw traps on valley rivers. I got to where I could usually ID them by sight, but in the early days I looked at a lot of upper fish lips lol! Here is another link to check out: http://fishbio.com/field-notes/wildl...e-you-attached

Sac Pikeminnow definitely eat juvenile salmonids. Its actually perfectly natural as the these species have co-evolved in the valley for thousands of years. What is unnatural about current Sac Pikminnow/salmonid relations is that the way we have altered the landscape and especially flow of our rivers has given Sac Pikeminnow (and other predators) an unfair advantage.....Check for that frenum next time you are out there hooking native minnows instead of steelhead. And, while you are at it, I hope you hook into a couple nice steelhead too Matt

[Jeff C.]

I caught a 10 lb pike minnow last year on a shad fly. This year I caught quite a few 4-6 lb ones that have slammmed my soft hackle or nymph but after the initial grab I knew I didn't have a steelhead on because there were no head shakes.

[Troutsource]

Matt, thanks for the info on the frenum. I'll take a closer look next time and post something here.

[Troutsource]

Finally encountered the nefarious minnows again today due to my extreme stealth tactics and mastery of fly fishing, and took the attached photo. Looks like a frenum, and thus a pikeminnow (Matt, maybe you can verify). I slayed a half dozen of them with my 7 wt. I also caught another minnow without a frenum and without the stripe. They were all going bananas on the tricos and I caught them swinging a tiny Copper John (they ignored the caddis pupa that was also on my rig). See photo of the trico graveyard. In that photo there's some algae that I never saw in any abundance in previous years except in frog water -- but now it's everywhere (little floating leaves).

What has this world come to -- I am posting about catching minnows. Last week I hooked a football-shaped quarter-pounder that took off like a rocket and shook the hook -- one step up from the minnow class.

[Notch]

Frenum= A frenulum (or frenum, plural: frenula or frena, from the Latin frēnulum, "little bridle", the diminutive of frēnum) is a small fold of tissue that secures or restricts the motion of a mobile organ in the body

Frenum = hardhead
No Frenum = pikeminnow

You can think of pikeminnow as kind of having "double lips". To me it looks like that fish has no frenum and would be a pikeminnow. At that size pikminnow should also have a more pronounced black stripe running down their side, compared to hardhead which are more consistent in color along their sides

[Bill Kiene semi-retired]

I guess we learn something every day.......thanks Matt

[STEELIES/26c3]

In that photo there's some algae that I never saw in any abundance in previous years except in frog water -- but now it's everywhere (little floating leaves).

Yo Paul, that is actually not an algae but rather an aquatic fern called Azolla sp (common name duckweed) and is yet another indicator of our river's warm-water plight.

The huge influx of pike minnows this year is due to habitat-substrate-abundance rather than migration related...

In most cases, less water = fewer fish but in this low-water year (and warmer water temps), there is a much greater diversity and distribution of aquatic plants.

Sunlight penetrates shallow water more effectively and hastens photosynthesis for plants like elodea, hydrilla etc...

Warmer water temperatures have also caused a greater variety and number of algal species and higher order plant species not normally found in the AR (like the Azolla and water hyacinth I've noticed in many places for the first time in many years).

This provides more habitat, cover and ultimately food (in the form of aquatic invertebrates) which exponentially spikes the population of cyprinids which are far more warm-water tolerant than the salmonids with which they share the water...

[Notch]

I also wonder if the warmer water temperatures are increasing the range of the Sac pikeminnow in the American River. They seem to have a temperature preference for warmer water, and if the water is cool - like it normally is below Nimbus - they typically stay farther downstream. In the lower Sac before water was pulled from deep in Shasta, pikeminnow were common all the way up to Keswick Dam and even spawned in the small seasonal tribs which flow into the upper river. Now they seem to be confined to the river downstream below Red Bluff. That might be good for the salmon smolts but I'm sure it disrupted the food web in one way or another...

[matt johnson]

Hey Troutsource looks like you've got those juvenile bug-eating American River Sacramento Pikeminnows dialed in!

Thanks for sharing the photo. I would have bet that you were actually catching Hardhead, but the lack of a frenum on that little guy definitely says Sac Pikeminnow....

So if you are like me now you are going to look closely at the upper lip margin of every olive/brown minnow you catch. You may even long for the days when any 'little olive/brown job" you caught on the river was quickly dismissed as another "darn squawfish" then quickly and unceremoniously tossed back into the river (hopefully not up on the bank like some knuckle-draggers do). Its madness!

[Mark Kranhold]

I'm thinking this forum needs to be updated Bill/Greg! We are going to need a Pike minnow/ Squaw fish section after this thread LOl !!