I dont know what sort of catfish you have but Wells cats like most very large fish, has a tremendous growth rate, especially where there is an abundance of available food. In the UK the growth rates can vary dramatically, The growth rates is about 3-4lbs a year this is the norm, as the cold shuts them down. But in Spain Ebro cats have a growth rate of ten to fifteen pounds per year but a 400lb one is a big fish in any lake.