Comparisons among paternal half-sib families by fulton and alometric condition factors and growth rate in curimbatá (Prochilodus lineatus)

Abstract

The determination of the condition factor in fish has been done to inform the growth, reproduction and survival in a specific environment. With the objective of comparing groups of paternal half-sibs it was conducted an experiment at the Fish Station of the State University of Londrina. It was used a sample of 253 fishes, sons of 10 Curimbata (Prochilodus lineatus) reproducers. In order to verify the possibility of their use in selection, Fulton and alometric condition factors were determined, as well as the growth rate. The results suggested that the progeny of the majority of the reproducers presented negative alometric growth (b < 3.0). There was only one exception, where the progeny of one male showed an isometric growth (b = 3.0). The identification of reproducers, which the progeny presented greater growth rate, was done by the alometric condition factor. The condition factor of Fulton, which uses the regression coefficient of b = 3.0, was not viable. Selection to improve the traits alometric condition factor and growth rate is possible with the utilization of the progeny selection, since these traits present low heritability (h2 = 0.20).