Editing Selective breeding (section)

===Finfish response to selection===

====Salmonids====

Gjedrem (1979) showed that selection of Atlantic salmon (''Salmo salar'') led to an increase in body weight by 30% per generation. A comparative study on the performance of select Atlantic salmon with wild fish was conducted by AKVAFORSK Genetics Centre in Norway. The traits, for which the selection was done included growth rate, feed consumption, protein retention, energy retention, and feed conversion efficiency. Selected fish had a twice better growth rate, a 40% higher feed intake, and an increased protein and energy retention. This led to an overall 20% better Fed Conversion Efficiency as compared to the wild stock.<ref>{{Cite journal | doi = 10.1016/s0044-8486(99)00204-5 | title = Feed intake, growth and feed utilization of offspring from wild and selected Atlantic salmon (''Salmo salar'')| journal = Aquaculture| volume = 180| issue = 3–4| pages = 237–246| year = 1999| last1 = Thodesen | first1 = J. R. | last2 = Grisdale-Helland | first2 = B. | last3 = Helland | first3 = S. L. J. | last4 = Gjerde | first4 = B. | bibcode = 1999Aquac.180..237T}}</ref> Atlantic salmon have also been selected for resistance to bacterial and viral diseases. Selection was done to check resistance to Infectious Pancreatic Necrosis Virus (IPNV). The results showed 66.6% mortality for low-resistant species whereas the high-resistant species showed 29.3% mortality compared to wild species.<ref>{{Cite journal | doi = 10.1016/j.aquaculture.2007.08.011| title = Response to selection for resistance against infectious pancreatic necrosis in Atlantic salmon (''Salmo salar'' L.)| journal = Aquaculture| volume = 272| pages = S62–S68| year = 2007| last1 = Storset | first1 = A. | last2 = Strand | first2 = C. | last3 = Wetten | first3 = M. | last4 = Kjøglum | first4 = S. | last5 = Ramstad | first5 = A. | bibcode = 2007Aquac.272..S62S}}</ref>

Rainbow trout (''S. gairdneri'') was reported to show large improvements in growth rate after 7–10 generations of selection.<ref>{{Cite journal | doi = 10.1577/1548-8659(1955)85[93:dortbs]2.0.co;2| title = Development of Rainbow Trout Brood Stock by Selective Breeding| journal = Transactions of the American Fisheries Society| volume = 85| pages = 93–101| year = 1957| last1 = Donaldson | first1 = L. R. | last2 = Olson | first2 = P. R. }}</ref> Kincaid et al. (1977) showed that growth gains by 30% could be achieved by selectively breeding rainbow trout for three generations.<ref>{{Cite journal | doi = 10.1577/1548-8659(1977)106<621:tgosfg>2.0.co;2| title = Three Generations of Selection for Growth Rate in Fall-Spawning Rainbow Trout| journal = Transactions of the American Fisheries Society| volume = 106| issue = 6| pages = 621–628| year = 1977| last1 = Kincaid | first1 = H. L.| last2 = Bridges | first2 = W. R.| last3 = von Limbach | first3 = B.| bibcode = 1977TrAFS.106..621K}}</ref> A 7% increase in growth was recorded per generation for rainbow trout by Kause et al. (2005).<ref>{{Cite journal | doi = 10.1016/j.aquaculture.2005.02.023| title = Genetic trends in growth, sexual maturity and skeletal deformations, and rate of inbreeding in a breeding programme for rainbow trout (Oncorhynchus mykiss)| journal = Aquaculture| volume = 247| issue = 1–4| pages = 177–187| year = 2005| last1 = Kause | first1 = A. | last2 = Ritola | first2 = O. | last3 = Paananen | first3 = T. | last4 = Wahlroos | first4 = H. | last5 = Mäntysaari | first5 = E. A. | bibcode = 2005Aquac.247..177K}}</ref>

In Japan, high resistance to IPNV in rainbow trout has been achieved by selectively breeding the stock. Resistant strains were found to have an average mortality of 4.3% whereas 96.1% mortality was observed in a highly sensitive strain.<ref>{{Cite journal | doi = 10.1016/0044-8486(93)90124-h| title = Resistance of a rainbow trout strain to infectious pancreatic necrosis| journal = Aquaculture| volume = 117| issue = 1–2| pages = 71–76| year = 1993| last1 = Okamoto | first1 = N. | last2 = Tayama | first2 = T. | last3 = Kawanobe | first3 = M. | last4 = Fujiki | first4 = N. | last5 = Yasuda | first5 = Y. | last6 = Sano | first6 = T. | bibcode = 1993Aquac.117...71O}}</ref>

Coho salmon (''Oncorhynchus kisutch'') increase in weight was found to be more than 60% after four generations of selective breeding.<ref>{{Cite journal | doi = 10.1016/0044-8486(90)90018-i| title = Genetic changes in the growth of coho salmon (''Oncorhynchus kisutch'') in marine net-pens, produced by ten years of selection| journal = Aquaculture| volume = 85| issue = 1–4| pages = 187–197| year = 1990| last1 = Hershberger | first1 = W. K. | last2 = Myers | first2 = J. M. | last3 = Iwamoto | first3 = R. N. | last4 = McAuley | first4 = W. C. | last5 = Saxton | first5 = A. M. | bibcode = 1990Aquac..85..187H}}</ref> In Chile, Neira et al. (2006) conducted experiments on early spawning dates in coho salmon. After selectively breeding the fish for four generations, spawning dates were 13–15 days earlier.<ref>{{Cite journal | doi = 10.1016/j.aquaculture.2006.03.001 | url = http://www.captura.uchile.cl/bitstream/handle/2250/6068/Neira_Roberto_GeneticII.pdf?sequence=1 | title = Genetic improvement in coho salmon (''Oncorhynchus kisutch''). II: Selection response for early spawning date | journal = Aquaculture | volume = 257 | issue = 1–4 | pages = 1–8 | year = 2006 | last1 = Neira | first1 = R. | last2 = Díaz | first2 = N. F. | last3 = Gall | first3 = G. A. E. | last4 = Gallardo | first4 = J. A. | last5 = Lhorente | first5 = J. P. | last6 = Alert | first6 = A. | bibcode = 2006Aquac.257....1N | access-date = 4 September 2015 | archive-date = 5 February 2020 | archive-url = https://web.archive.org/web/20200205110444/http://repositorio.uchile.cl/?sequence=1 | url-status = dead }}</ref>

'''Cyprinids'''

Selective breeding programs for the Common carp (''Cyprinus carpio'') include improvement in growth, shape and resistance to disease. Experiments carried out in the USSR used crossings of broodstocks to increase genetic diversity and then selected the species for traits like growth rate, exterior traits and viability, and/or adaptation to environmental conditions like variations in temperature. Kirpichnikov ''et al.'' (1974)<ref>{{Cite book | doi = 10.1016/b978-0-444-81527-9.50006-3| chapter = Selection of Krasnodar common carp (''Cyprinus carpio'' L.) for resistance to dropsy: Principal results and prospects| title = Genetics in Aquaculture| pages = 7| year = 1993| last1 = Kirpichnikov | first1 = V. S.| last2 = Ilyasov | first2 = I.| last3 = Shart | first3 = L. A.| last4 = Vikhman | first4 = A. A.| last5 = Ganchenko | first5 = M. V.| last6 = Ostashevsky | first6 = A. L.| last7 = Simonov | first7 = V. M.| last8 = Tikhonov | first8 = G. F.| last9 = Tjurin | first9 = V. V.| isbn = 9780444815279}}</ref> and Babouchkine (1987)<ref name=Babouchkine/> selected carp for fast growth and tolerance to cold, the Ropsha carp. The results showed a 30–40% to 77.4% improvement of cold tolerance but did not provide any data for growth rate. An increase in growth rate was observed in the second generation in Vietnam.<ref>{{Cite journal | doi = 10.1016/0044-8486(93)90064-6| title = Selection of common carp (''Cyprinus carpio'' L.) in Vietnam| journal = Aquaculture| volume = 111| issue = 1–4| pages = 301–302| year = 1993| last1 = Mai Thien Tran| last2 = Cong Thang Nguyen| bibcode = 1993Aquac.111..301M}}</ref> Moav and Wohlfarth (1976) showed positive results when selecting for slower growth for three generations compared to selecting for faster growth. Schaperclaus (1962) showed resistance to the dropsy disease wherein selected lines suffered low mortality (11.5%) compared to unselected (57%).<ref>{{Cite journal
 | pmid = 1248737
| pmc = 1213447
| year = 1976
| last1 = Moav
| first1 = R
| title = Two-way selection for growth rate in the common carp (''Cyprinus carpio'' L.)
| journal = Genetics
| volume = 82
| issue = 1
| pages = 83–101
| last2 = Wohlfarth
| first2 = G
| doi = 10.1093/genetics/82.1.83
}}</ref>

====Channel Catfish====

Growth was seen to increase by 12–20% in selectively bred ''Iictalurus punctatus''.<ref>{{Cite journal | doi = 10.1016/0044-8486(83)90387-3| title = Response to bidirectional selection for body weight in channel catfish| journal = Aquaculture| volume = 33| issue = 1–4| pages = 73–81| year = 1983| last1 = Bondari | first1 = K.| bibcode = 1983Aquac..33...73B}}</ref> More recently, the response of the Channel Catfish to selection for improved growth rate was found to be approximately 80%, that is, an average of 13% per generation.