Markets require that baitfish and feeder fish remain small.
Ninety percent of bait-size goldfish are sold at 3 pounds per thousand fish. A large number of fathead minnows are sold as bait at 3 pounds per thousand, and crappie-size golden shiner bait run about 5 pounds per thousand. To keep them small they are stocked at 500,000 or more per surface acre, and they are fed as little as one percent of body weight per day. Compared to other types of fish culture, baitfish are heavily overstocked and underfed. Crowding increases the incidence of disease by a variety of mechanisms, including poor water quality, easy transmission from fish to fish, and immunosuppression.