The normal lifespan of a healthy channel catfish may be around 6 to 10 years, depending on the fishing intensity in that area. Some wily and legendary catfish (Old Jake in my hometown’s fishing pond, for example) have been known to live 18-20 years (one specimen was even logged at 40 years) and tag in at well over 35 lbs. The size and actual lifespan will depend, of course, on the size and configuration of the pond, the water quality and whether there’s a well-managed feeding program. Usually, only a feeding program will produce the large 3-4’ monsters that star in the best fish tales.
Although described as scavengers, channel cats are known to eat small fish once they reach a certain size, and some have been known to eat birds. In some natural waters smaller fish may, in fact, make up to 75% of a cat’s diet. Unless your stocking budget permits the loss of fingerlings, it’s a good idea to aggressively harvest any cats 18” and above. In fact, if you’re planning on raising channel cats in your pond, it’s a good strategy to stagger their ages by restocking every year or two and harvesting older cats regularly. Without adding new fish, your population will age and gain experience, and you’ll end up with a few wily old timers who are too cautious to take the bait but are willing to consume the newbies. A few years’ worth of relatively naive cats will be much more likely to satisfy your itch to fish.