Tilapiaare mainly known as freshwater fish that inhibiting ponds, lakes and river butsome of it species live in brackish water due to their tolerance to highsalinity. Some country claimed this species as invasive species such asAustralia but farmed extensively by many countries in Asia region such asMalaysia. Farmed tilapia production is about 1,500,000 tones (1,500,000 longtons; 1,700,000 short tons) annually with an estimated value of US$1.8 billion(De Silva, 2004), about equal to that of salmon and trout.
Thus, many fish farmers attempt to makedifferent technique in breeding to increase their production in aquaculturepractices and one of the technique is crossbreeding. Crossbreeding is themating of individuals of different species, varieties or lines to find newspecies or varieties that have potential to be introduce. This process combinesthe best of each individual breed and its genes into a more heterozygous animal(Burnside, 2004). Hybrids show characteristics of both parents and when ahybrid shows characteristics superior to both parents, it is said to havehybrid vigour or positive heterosis, which is the goal of breeding (Masser,1998). Moreover, crossbreeding also has been used to produce hybrids that haveimproved growth rates, survival rates, lower food conversion rates, improveddisease resistance, etc.
(Tave, 2003). Common Red tilapia (Oreochromis spp.) grow rapidly on formulated feeds with lowerprotein levels and tolerate higher carbohydrate levels than many carnivorousfarmed species. They can also accept feeds with a higher percentage of plantproteins. It is easy to breed tilapia and culture them intensively andeconomically.
They are relatively resistant to poor water quality and disease.Their hardiness and adaptability to a wide range of culture systems has led tothe commercialization of tilapia production in more than 100 countries. Theirwidespread consumer appeal will fuel the expansion of the tilapia industry foryears to come.
Black tilapia (Oreochromis mossambicus) are hardy and can easily establish innatural waters (GISD ,2006). This species also known for their high tolerancetoward water salinity and but poor in breeding performance. The majorconstraint of Oreochromis niloticusis related to its commercial value and easy production, while Oreochromis mossambicus with its hardyand high salinity.