For us, we don't have circle hooks here. However, we do use shorter shank style hooks like octopus hooks. You can use longer shank hook as well and I've used them before. I think preference is really based on which bait you're using. If you choose to use a dead baitfish or worms, using a hook with longer shank helps you bait stay better on the hook (better yet, use livebait hooks which is reverse barbs on the shank). When I use chunks or slivers of pork liver, I choose to use a octopus style hook. The shorter shank is good enough to hold the pork liver, yet leaving the sliver of liver to flap in the current
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I don't find hook choice very important to channel cats. They're not too hook shy and when they bite, they'll either gulp in small baits or chomp on larger baits. Once your bait is in its mouth, it'll only stay in there. I did have channel cats spit out my bait before because the fish felt some line tension when my line was taunt and the drag was tight. So usually, when I'm getting bites, I feed it a little bit of line and count about 2 seconds before setting the hook. So far, all my fish has been hooked in the upper jaw and corner of the mouth. You don't want to wait too long or else you may gill hook or gut hook the fish
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However, my fish were usually caught in currents...so I think once the fish locate a scent trail and found my bait, it has already determined that my bait is food and it doesn't think twice about biting. In a still water situation, the fish may be a bit more picky.
Oh, to elaborate a bit on the pork liver...We cut a piece about 1/4 inch thick and about 2-3" long. With the octopus hook, we use about a #4-#2. I would thread the liver twice onto the hook on one end, leaving a "tail" of liver to flap in the current. Try to cut the liver so that you can push your hook through the membrane of the liver. It helps to keep the liver on the hook much better that way.
All my big cats (3-6lb range) has managed to cut my line (10lb leader, 8lb main) in the rocky areas that I fish...I've only managed to land small 1lb fish so far. Next summer, I'm going to use my musky baitcaster and 50lb PowerPro for them