The number I was taught at Iowa State was 400 lbs/acre in an Iowa pond with 50-100 of that being predators. Due to the rich soils and crop fields in most of the watersheds these ponds are considered naturally fertilized (or overfertilized); this was without pellets or aeration.
At Mississippi State I was told in Mississippi an unfertilized, unfed, unaerated pond was likely to hold 100 to maybe 200 lbs/acre.
IIRC catfish production ponds with massive amounts of feeding and uber-aeration can grow 1,500 lbs/acre.
