Other Production Methods 



Recently there has been a great deal of interest in home fish 

 fanning for family consumption. The use of small ponds or plastic 

 swimming pools as fish rearing facilities for personal use is 

 becoming popular. With the development of effective and economical 

 filters to remove organic wastes from the water, home fish farming 

 may increase further in popularity. Small-scale mollusc culture 

 under piers and in salt and brackish water ponds at the edge of the 

 sea also has potential. 



Genetics and Reproduction 



Warmwater and Coolwater Finfish 



Most warm and coolwater fish are produced by natural spawning in 

 ponds. With some species, the broodfish are removed after spawning 

 to keep them from eating the fry, to facilitate handling small 

 fish, and to reduce competition. Channel catfish egg masses are 

 usually collected from spawning containers in a pond and then moved 

 to a hatchery incubation facility. 



Hormone injection of broodfish to induce spawning is practical for 

 some species. Striped bass broodfish are usually captured from 

 rivers or lakes just prior to spawning, injected with hormones, and 

 artificially spawned in a hatchery. This technique has also been 

 successfully used to produce hybrid crosses of normally 

 incompatible species. Sex steroids and hybrid crosses are also 

 being evaluated for their potential to produce monosex or infertile 

 fish populations. These methods promote more rapid growth rates 

 and prevent animals that might escape to the wild from spawning and 

 overpopulating to the detriment of indigenous species. 



Coldwater Finfish (Salmonids) 



Nonanadromous salmonids, such as trout, have been cultured in this 

 country longer than has any other aquaculture species and their 

 life histories are well understood. The rainbow trout is the most 

 important species reared for sport fishing purposes. Strains and 

 hybrids have been selectively developed for enhanced growth, 

 disease resistance, age and season of sexual maturity, body color, 

 and adaptation to hatchery conditions. Additional research will be 

 required to understand and control sexual maturity, to produce 

 monosex fish, and to develop methods for determining the sex of 

 young trout . 



Genetic research on anadromous salmonids has been directed at 

 improving disease resistance, growth, and maximizing returns to 

 freshwater. Additional research is needed to characterize strain 

 differences, to assess the genetic composition of different 

 spawning runs, to insure identification and protection of wild 

 stocks, and to maintain a diverse genetic pool. 



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