Rod, two common sucker species are prevalent in Ozarks streams - the River Redhorse and the Northern Hogsucker. Snagging season for suckers is a big deal in the Misery Ozarks.
As previously mentioned all you need is a lightweight rod rigged with nothing but a hook/worm and a split shot if you want to catch them the sporting way. You've already noticed that they are quite skittish. Approach quietly from downstream, pitch your worm a couple or three feet upstream from the school (they will orient facing the current unless they're spooked or swimming back to the lower end of the hole to start another feeding run). This will sound funny, but watch what happens when one of them spots your worm sinking to the bottom - the fish will swim to the bait, sniff it, then start to eat it - lips extend once, lips extend twice, lips extend three times - lift the rod tip and virtually every time you will have them hooked in the corner of the mouth. Lift on one or two you'll miss. Lift on four the fish swallowed your hook.
They're super easy to butcher - scrape the scales off, remove the filet, score down to the skin every 1/4" or so. Dip in your favorite fish fry mix and toss em into hot grease. It will be some of the best fish you've ever eaten.
Oh... I have no idea if the OPV will whistle at me when/if it pops. It looks like your garden variety OPV that would be found on an air compressor, but I can't imagine that the volume/pressure our diffusion pumps run at would cause it to make much noise.
