Channel & Blue cats typically spawn when the water temp reaches between 70 & 84 degrees with 80 degrees being generally considered optimum. Flatheads typically spawn at between 66 & 75 degrees with right around 70 being optimum. Since the current water temperatures in most of the local rivers,lakes & streams are between 70 and 80 degrees we're toward the end of the spawning time for most Flatheads and are just getting into spawning time for Channels and Blues. Contrary to what alot of catfisherman will tell you, different catfish species don't spawn EN MASSE. It's usually more a staggered type thing where only a certain percentage of fish will be spawning at any given time over what can be as long as a 4 to 8 week period depending upon changing weather,water temps & levels,etc.
Often during the spawning season a good percentage of fish may still be in pre spawn mode and actively feeding,but they're often not found in areas where catfishermen usually catch them either because they haven't settled into their typical post spawn areas yet (this is ESPECIALLY true of Flatheads) or are on the move toward spawning areas. Hope this helps.
If the conditions are right (especially warm spring weather) some channel cats may spawn earlier in the year (usually in May here in Ohio in waters that heat up earlier/faster). These fish could grow to from anywhere from 2 to 5 inches in a two month or so period. Flathead fry are actually of similar size at a young age (when hatched they average just less than a half inch).
Dude, thank you very much for the detailed response.
So here's the deal. I get out for some wading. I know this lady who lives right on a Central Ohio stream I haven't fished in 5 years. My son and I are supposed to go together last night, but he ends up taking a baseball upside his dome in his game, so long story I go alone for an hour and a half.
Not the greatest smallie stretch going, more of a catfish spot. And I'm struggling. I probably caught 2 fish, both like 12"ers....it's slow.
So I'm sitting on a log, taking a break and "thinking", when it dawns on me. When in Rome...
I'm not going with how many smallies I caught or how big, because my camera/phone was in the car and I don't need the hassle, but it got way better in a hurry. Way, way better.
I concentrated on what I thought was water where catfish would spawn ( I guessed), tried to find an area that I think smallies would hold to ambush those spots (guessed again) and figured the fry, if there was any, would be about this big: (edit: Picture sucks worse than I thought. The brownish madtom in the upper left is what I threw. Maybe 2 1/2")
Even a blind squirrel stumbles over a couple nuts every once in a while.
I think that the spawning times were mixed up, channels and blues spawn first then flatheads spawn. But either way the spawns are really close to each other. Both channels and flatheads spawn between 70 F and 80 F.
I'm a little confused here, but all I know is that in the Muskingum and Ohio Rivers you WILL find all 3 fish spawning at the same time, but usually blues, then channels, then flatheads, all overlapping times and usually not in the same areas and of course not every fish of the species at the same time just as any other species of fish. It's not hard to tell if they are spawning though, because wherever you see a bunch of little ones.... daddy won't be far from them and sometimes momma will be around as well.
There isn't really a DEFINITE time that these catfish species spawn. Last year the spawn seemed later than usual for both channels AND flatheads. I caught spawning male channels from July all the way into September last year. The info i posted here on the typical water temps for the species was from 3 or 4 different sources. They all said basically the same thing. But my personal experience has varied widely from that info as well. I caught 3 flatheads just a week ago from the muskingum and none of the 3 showed any marks or signs of having recently spawned. That being said i've seen pics of flatheads that were caught from the same stretch of river over a month ago that were obviously post-spawn. None of the channel cats i've caught so far this year have showed any obvious signs of spawning though i've seen pictures of many caught over the past 6 weeks or so in the Muskingum,Ohio & Scioto that did. I also caught a ridiculous amount of 3" to 4" channels while fishing for bluegill at the spillway at Dillon lake over a month ago so go figure. I'm sure i'll catch spawning males with swollen and bumpy heads well into august and maybe even september if last year is any indicator. It's definitely an in-exact and not at all like clockwork process.