With no correlation found between body weight and cold tolerance, and the 22-cM distance between the two QTL, we infer that different genes, which happen to be in the same linkage group, influence these two traits.
Both QTL show overdominance effects (Table 4).
These two traits were also shown to have a large dominant effect in quantitative genetic studies of different tilapia species and hybrids (Wohlfarth et al., 1983; Cnaani et al., 2000).
Due to that dominance, tilapia production in the Israeli aquaculture industry is based largely on interspecific hybrids.