Fernanda De Mello*, Carlos AL
Abstract
Fish farming is a significant part of the total aquaculture production, thereby, it is very important develop methods and strategies that maximize productivity per area used becomes essential. Fundamentally, the genetic improvement of the population proceeds through determination of a selection criterion that meets the current production system, as well as in the correct choice of the animals that participate in the formation of the next generation. However, very few estimates of additive genetic variance and heritability are available for wild populations, particularly for fish. Genetic parameters and (co)variance components were estimated for body weight and morphometric traits of economic interest at 12 and 24 months old Colossoma macropomun. Heritability estimates for body weight and morphometric traits were high, ranging from 0.17-0.46 at 12 months and from 0.25-0.49 at 24 months. The body length had a higher heritability estimate at the 12 months (0.46) and the daily weight gain had the higher heritability estimate at 24 months (0.49). The common family environment effect showed a 20% share in the total variation for body width; however, for the other traits this effect was lower ranging between 7 and 11%. The results estimated here indicate that the growth variations observed between animals have a genetic origin, which will be largely passed to their progeny. Our data show that morphometric traits, such as length and body weight can retain high levels of heritability even when total phenotypic variance is high. Thus, the estimated genetic parameters for body weight, daily weight gain and morphometric traits can be improved by selection in both stages analyzed, allowing to predict the response to selection.