Slimcat and I have been having some discussions about catfish management in KY and he asked me a few questions about their biology. I thought that might be interesting for others, so put it in a new thread. Question: How old a 50" blue or flathead might be. Answer: It's tough to find this information because the older a catfish gets, the harder it is to age them. But, there is still some data out there. For flatheads, a 44" fish was 10 years old in the tallahatchie river, MS. ON average, flatheads that were 30" long were between 9-14 years old. Blue catfish in oklahoma were 44" at age 11 and one fish that was 55" was 21 years old. In KY and Barkley lakes, a 38" fish could be from 11-19 years old. Individual fish grow at different rates. We have been sampling up to now with trotlines, and we don't see the largest fish (50") in those samples. This year we will be using some other methods and I think our catch rates will be much better. The growth of catfish in KY and Barkley lakes is very good when compared to other lakes in the mid south. Probably higher than in the Ohio river. Places that have better growth are farther south where the growing season is longer. Question: What is the relationship between size of catfish and their spawning or hatching success? Answer: Larger catfish produce many more eggs as they grow. The hatching success is still high for large fish. What is a bit misleading is that fish are like people as they get old and decrepid, they have trouble doing things. AS their health declines, they may have a spawn or two that aren't as good before they die. But, until they get near death, their spawns will be successful. Egg hatching success and survival of young fish is fairly low for all species of fish including catfish. So, the number of successful eggs hatching doesn't have to be very high to have what we consider a successful spawn. If a large catfish lays 400,000-600,000 eggs, only a small percentage of them needs to survive to affect the fishery.