Fish Hatchery Management - fisheries & aquaculture

NUTRITION AND I'E,EDINGearthen ponds. This method generally results in low yields and isunpredictable.Interest in supplemental feeding of bass has been renewed in recentyears due to successful experimental use of formulated pelleted feeds withlargemouth bass fingerlings. Attempts to train swim-up bass fry to feedexclusively on formulated feeds or ground fish flesh have been unsuccessful,despite the use of a variety of training techniques. The best success insupplemental feeding has been obtained by rearing bass fry on natural feedto an average length of 2 inches in earthen ponds before they are put onan intensive training program to accept formulated feed. A moist feed, suchas the Oregon moist pellet, or a quality dry feed such as the W-7 coolwaterfish feed may be employed. The success of this Program has been correlatedwith initial fingerling size, coupled with sound management practices.The following steps are suggested for an intensive feeding program withbass:By conventional techniques, rear bass fingerlings on natural feed inearthen ponds to.an average total length of 2.0 inches. Harvest and movefish to raceways and tanks. Grade fish carefully to eliminate "cannibals,"because uniformly sized fingerlings are needed. Stock the tanks at 0.15-0.4pounds per cubic foot of water (3,000-7,500 fingerlings per tank).Treat the fish prophylactically with 4 parts per million acriflavine for 4hours. Heavy parasite infestations may require treatment with formalin or asimilar chemical. Provide ample aeration during treatment'Begin feeding a {-inchfeed granule the following day. Feed at l- to 2-hour intervals, five or more times daily. Feed slowly and carefully becausebass will not pick up sunken food particles from the bottom of the tank.Automatic feeders are excellent for this Purpose.If fish are reluctant to feed, supplement the granule with ground fresh orfrozen fish.Clean tanks twice daily and remove all dead fish daily.Begin feeding a $-inch granule as soon as the fingerlings are feedingwell and able to ingest it.Perform grading as needed to reduce cannibalism.After 10-14 days, 65-75% of the fish should be on feed' Reports of90-95,/o success are not unusual. The fish should double their weight duringthis 2-week period.At 2-3 weeks. remove all nonfeeders and move the fish to ponds or raceways.stock ponds at 10,000 per acre. Feed and maintain fish in a restrictedarea for 2-3 days, then release them to the remainder of the pond.Grow the bass to 4 inches on a ]-inch pellet. Table 30 presents a suggestedfeeding guide that can be used when formulated dry feeds are givento bass fingerlings in raceways or ponds.