Genetic and zootechnical evaluation of two varieties of Nile tilapia (O. niloticus var. Red-Stirling and O. niloticus var. Chilatrada) for the establishment of program for the mass production of a hybrid of red tilapia

Abstract

The production of fish in captivity has taken on an important role in the total amount of fish available for human food, the production of fishmeal and oil. Changes in eating habits, that is, the search for foods of animal origin with low levels of cholesterol and high protein value, has placed fish on the daily menu of many populations. Tilapia is a fish of African origin, however, it is farmed in various countries in the northern and southern hemispheres. It was introduced into Brazil in the 1950s and today it is to be found almost throughout the country, in commercial farms as well as reservoirs and artificial lakes. Among the varieties of tilapia used in pisciculture, the Nile tilapia (Oreochromis niloticus) has been the most widely bred. Red tilapia is a mutational variant which was discovered in the 1960s, in Thailand. Among the tilapia species in which the mutation towards the color red was observed, the O. niloticus is outstanding. The present project aims to develop an interspecies hybrid of tilapia which combines the superior zootechnical qualities of the chilatrada variety of O. niloticus with the red coloration of the O. niloticus Red-Stirling variety so prized by the market. The results presented in phase 1 of the present project underlined the potential of the Red-Stirling variety in terms of its zootechnical performance in field conditions, as well as its low index of endogamy, an important factor for the implementation of practices of genetic improvement through selection. Thus, with the establishment of phase 2 of the present project, the goal will be to produce beginning in the second year 3,410,000 young fish per year. Investment in this phase will enable the setting up of an intensive and continuous system for the production of young fish that will be monitored through the analysis of genetic markers to assess their quality. (AU)