Welcome to the strange world of angling for one of the most frustrating fishes in the world.
Back in the 80's, when I was 16, I received the book Fishing for Buffalo, by Tom Dickson and Rob Buffler, as a gift from a good friend. In the book, they spoke of catching "so many Carpsuckers that our arms got tired" at a dam on the Cannon River. Once I got my driver's license, I went there. Alas, the dam was gone and there were no carpsuckers to be found. I thought they were some rare species that I could easily catch if only I could find them. But where were they?
In the early 90's, I made some progress. The internet made it easier. There were lots of them in Florence Lake in southern Minnesota, so I dragged a mob of intrepid fishermen down there to try for them. Alas, Florence Lake was gone. My fishing buddies caught creek chubs and white suckers in a creek where the lake used to be.
Then, I discovered Wisconsin. Finally, a river with more carpsuckers than anything else. Around 1996 I scored a copy of the Wisconsin DNR stream survey database and ran a customized carpsucker query. The results came out as a list of strange numbers and codes scrolling by on a greenscreen monitor. I had finally found them.
Two weeks later, I stood on the high banks of that river with my brother Andy by my side. Below us was a large pool. The water was clear enough for us to see every scale of the fish in the pool below. There were hundreds of carpsuckers suspended in there, floating in the still water like lazy ghosts. We laughed as we prepared our tackle, expecting to have the best day of fishing in our lives. We were seasoned roughfishers. We had caught every fish we had ever encountered. A hook, a worm, and a sinker was all we needed.
We were wrong. Everything we knew about these fish was wrong. We had what can only be described as the most frustrating fishing experience we had ever experienced. We went home skunked, depressed, and perplexed. We had fished three rods, floats, bottom-rigs, flies, doughballs, everything.
Luckily, that same year we launched roughfish.com, and dozens of skilled anglers were about to join the hunt.
Over the next decade, the Carpsucker Underground formed. It wasn't called that, and still isn't. But a dedicated cadre of like-minded anglers began to unravel the puzzle. All of us compared notes and results. A woman in Chicago chummed them in with groundbait and caught them on tiny maggots. She called them "breath-feeders". One guy had caught one once on a rapala. I had snagged one in the face and swore it had reacted to my fly. A Canadian flyfisher swore to me that if you caught one, you had to throw away your tippet or you would never catch another. Above all, we learned about them. As it turns out, they were found in good numbers in most of the rivers we fished in the south. But they were hard to catch - very hard. We didn't know why.
I won't claim to be good at it even today. But here's what we know.
This might seem pretty obvious, but there's more to it than it seems. Carpsuckers have big eyes and a sensitive lateral line. Just getting into casting range can be impossible. The first lesson I learned about them was to stay the hell out of the water. You simply cannot approach them in waders. I duelled a school of river carpsuckers many years ago in a trout stream, and their sensitivity to ripples in the water and flyline moving overhead made trout look like oblivious lunkheads. So what does this mean?
Carpsuckers are best fished from concealment, on the bank. Don't make waves, don't use a big sinker, and don't try to wade up to them. Use small weights and very light line, and don't cast anywhere near them.
All of the illustrious members of The Carpsucker Underground had watched these fish feed for many hours. The fish slowly and painstakingly make their way across sand, gravel, or silt. They don't hunt for food like a predator, they breathe in tiny bits of food that happen to be right under their nose. If it's not under their nose, they won't go hunting for it, even if it's a delicious morsel only inches away. So this means ...
You must place a stationary bait directly in the carpsucker's path. Groundbaiting can encourage them to feed in your general vicinity.
While their mouth is big enough to engulf many typical baits, the opening to their esophagous is measured in millimeters. Analysis of stomach contents results in a confusing menagerie of microscopic things: microscopic algae, tiny larvae (tendipedids), miniscule crustaceans (cladocerans), and the smallest of aquatic insects.
You must use small hooks and tiny baits to catch feeding carpsuckers. #14 scud hooks, small circle hooks, and tiny pieces of worm will work. A single kernal of canned corn can also be effective.
This is an understatement. The Chicago Match-Fishers use a tiny, sensitive float rigged with a dozen tiny flecks of shot the size of pepper grains, A carpsucker will breathe in the bait so gently that the float will barely move at all. Bite detection for carpsuckers without using a float is almost impossible. In cloudy water, a float and leger rig is probably a good option if you know that carpsuckers are present in good numbers. But in clear water, you can detect the bite by sight. Depending on the angle, you might see the mouth extend or quiver. Or you might see the pectoral fins quiver. The fish might just stop and twitch its lips.
Don't expect the carpsuckers to pull on your line, ever. Sometimes, you'll get lucky and they'll hook themselves. But you have to be tense and ready to strike when they approach your bait, and when they have it, you have to strike quickly before they spit it out.
Sometimes, these fish just suspend without feeding and become torpid. By suspend, I mean exactly that - they hang motionless, well off the bottom. In these cases, even a perfect presentation is useless and you're going to have a bad time if you keep at it.
Be sure the fish are actively feeding before trying to catch them. You can usually tell that they are feeding because they move slowly upstream while hugging tight to the bottom. If they're not, you're better off looking for some active fish than fishing for the inactive ones.
The gear I use is
8 gama octopus hook
4 pound flouro
weight to hold it's spot in the current and easily reposition without spooking the fish
They are not chasing your bait you just have to get it in front of them and watch your fleck of crawler close and set the hook when the fish suckes it up. Sometimes you win most of the the time the fish does.
I use exclusively braid for carpsuckers.
A number 12-14 hook with a piece of a waxworm. For weight a tiny shot, just enough to hold in the current.
A spookier fish you will not find.
I typically watch the fish. if they are moving downstream I don’t bother. If they are working a straight line upstream then turning to drift downstream to start again I will fish for them. This is active feeding in a territory.
I find this situation to be the best.
I will set my bait in their path and kneel down or lay down. Often I will cast 10 feet ahead of them and wait. It could take 20 minutes for them to work up to the bait. When they are over the bait they will often keep going, but watch their pectoral fins. When they strike the bait their fins will flip as they suck in the bait, its subtle but a better indicator of a strike. When you see that set the hook.
We have tried experiments with braid vs Mono on highfins and quillback. Often they will swim away from the bait if we use mono and wont be frightened by the braid. Why I am not sure.
Perhaps the braid has a more natural feel.