The introduction of Nile tilapia and subsequent speed in production as well as enhancement of cultured species was carried out without regard for management of genetic resources. Moreover, the effect of natural disasters such as floods, typhoons, earthquakes and tsunamis on the genetics of this species is quite pronounced in Asia. Hybridization of tilapia occurs both naturally and artificially. However, artificial hybridization occurs more frequently since man is trying to improve production within the shortest possible time. Aquaculture of tilapia presents some genetic problems which was classified variously (Kocher et al., 1998, Ambali and Malekano 2004). There is the problem of inbreeding and associated genetic depression. Tilapia strains
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However, the production of these hybrids has been poorly managed and cases of gene introgression abound (Jinliang 2011, Sukmanomon et al., 2012b, Wu and Yang 2012, Rahman et al., 2013). Finally, there is some evidence that domesticated improved tilapia are being introgressed by wild strains causing declines in productivity, with an example of the GIFT strain in Fiji coming in handy (McKinna et al., 2010) as well as in the Bang Phra strain (Sukmanomon et al., 2012a) and as for the red tilapia, Popma and Lovshin (1996) reports that there is relatively no reliability in predicting the growth of red tilapia since parentage records of various strains cultured world over is unknown.
Temperature Tolerance
Tilapia culture in Thailand requires the tolerance of the species to both temperature and salinity variations. The production of hybrids that can effectively perform in different water environments holds the key to sustainable aquaculture in the face of climate change. The Northern part of Thailand experiences low water temperatures in the winter season and reproductive performance of tilapia is affected. Optimal water temperature for tilapia is in the range of 25 to 35oC with 28 to 32oC being adequate …show more content…
mossambicus x O. aureus) size was not correlated with cold tolerance. Rapid temperature declines negatively affect tilapia survival while every degree Celsius rise in temperature gives tilapia almost a threefold chance of survival (Wilson et al., 2004). Temperature changes can be drastic or gradual depending on environmental conditions as well as rearing conditions, while tolerance is linked to both the environment (Charo-Karisa et al., 2004, Charo-Karisa et al., 2005) and genetic effects (Charo-Karisa et al., 2005). Paz (2003) reported that fluctuation in temperature using temperature regimes affect the tolerance of tilapia to low temperature regardless of strain or
However, the production of these hybrids has been poorly managed and cases of gene introgression abound (Jinliang 2011, Sukmanomon et al., 2012b, Wu and Yang 2012, Rahman et al., 2013). Finally, there is some evidence that domesticated improved tilapia are being introgressed by wild strains causing declines in productivity, with an example of the GIFT strain in Fiji coming in handy (McKinna et al., 2010) as well as in the Bang Phra strain (Sukmanomon et al., 2012a) and as for the red tilapia, Popma and Lovshin (1996) reports that there is relatively no reliability in predicting the growth of red tilapia since parentage records of various strains cultured world over is unknown.
Temperature Tolerance
Tilapia culture in Thailand requires the tolerance of the species to both temperature and salinity variations. The production of hybrids that can effectively perform in different water environments holds the key to sustainable aquaculture in the face of climate change. The Northern part of Thailand experiences low water temperatures in the winter season and reproductive performance of tilapia is affected. Optimal water temperature for tilapia is in the range of 25 to 35oC with 28 to 32oC being adequate …show more content…
mossambicus x O. aureus) size was not correlated with cold tolerance. Rapid temperature declines negatively affect tilapia survival while every degree Celsius rise in temperature gives tilapia almost a threefold chance of survival (Wilson et al., 2004). Temperature changes can be drastic or gradual depending on environmental conditions as well as rearing conditions, while tolerance is linked to both the environment (Charo-Karisa et al., 2004, Charo-Karisa et al., 2005) and genetic effects (Charo-Karisa et al., 2005). Paz (2003) reported that fluctuation in temperature using temperature regimes affect the tolerance of tilapia to low temperature regardless of strain or