Taken directly from their fw.ky.gov a growth rate study of catfish from the Ohio river. (2007)

The oldest male flathead catfish collected was a 31-year-old fish that measured 41 inches and weighed approximately 38 pounds while the oldest female flathead collected was 21 years of age, measured 33 inches and weighed approximately 18 pounds.

Similar differences in growth rates for male and female blue catfish are also being observed in the Ohio River. By age 15, male blue catfish (36 inches) begin to outgrow female blue catfish (29 inches). The largest female blue cat collected was 24 years old, measured 33 inches and weighed nearly 15 pounds compared to a 24 year old male that measured 45 inches and
weighed just over 50 pounds.

Flathead
male 31 y/o = measured 41" and weighed only 38 lbs...... a female flathead 21 y/o measured 33" and weighed only 18 lbs!

bluecat

female 24 y/o measured 33" and weighed only 15 lbs..... a 24 year old male measuring 45 " weighed only 50.