I can't remember the technical term, but when fishing in Minnesota we called 'em "suckerfish". About 3" long bait fish, bottomfeeder with a circular mouth that faces downward. GREAT for Northern Pike!
Years ago my future wife & I were fishing the NE side of Lake Winona off the public pier with spinner/crank baits....nothin'. This lady comes up, taps in a pole holder with a hammer and then loads up the hook with a suckerfish and just tosses it out to the water just a few feet from shore. She goes back to her car to get some tea when the huge bobber she has starts moving slowly out towards the lake...then down under the water. We shout out to her that she's got something and she hussles over to start reeling it in. She's fighting this thing and fighting and asks for some help. I help her reel it it and get it on shore. Northern Pike...at least a 10 pounder! The fish looked like a dog with no legs it was BIG. We got her fish into her ice-box and she went home.
