A method for the controlled production of largemouth bass, Micropterus salmoides, Lac. fry is described. The method was based upon use of artificiallyfed brood fish which were stocked into small earthen ponds equipped with nylon felt spawning mats. Eggs deposited on the mats were separated, cleaned and incubated in a Heath Vertical Incubator. Fry hatched in one to two days and were held until swimup in holding troughs or shipped during the yolk sac absorption stage. A trial of the technique in 1972 resulted in approximately 2,714,000 eggs being collected from 563 fish stocked in seven O.I-acre ponds. From these eggs, 1,564,000 fry were hatched and survived (57.6 percent) to swimup or for shipment as sac fry. Twenty-two percent of the eggs collected were infertile according to examination of samples removed during processing. Subtracting this percentage from the total number of eggs collected gives an estimated 2,117,000 which could have hatched. Usable fry production was 1,564,000 or 73.9 percent of the viable eggs incubated. Five age classes of adults were included in the stocking. Best egg production was from five-year-old females, with an average of 2.0 spawns each, followed by two-year-olds with 1.9 spawns each. Three-, four- and one-year age classes produced 1.3, 0.9 and 0.8 spawns respectively per female stocked. The advantages and disadvantages of the method are discussed along with some possible applications.
