Comparisons among paternal half-sib families by fulton and allometric condition factors and growth rate in curimbata (Prochilodus lineatus).

摘要

The determination of the condition factor in fish is performed to determine the growth, reproduction and survival in a specific environment. The objective of this study was to compare the growth rate of paternal half-sibs using Fulton and alometric condition factors. The study was performed in Fish Station of the State University of Londrina, Parana, Brazil. 253 fishes which were progenies of 10 Curimbata (Prochilodus lineatus) reproducers were used in the study. In order to verify the possibility of their use in selection, Fulton and alometric condition factors were determined, as well as the growth rate. Results revealed that the progeny of 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 made use of the regression coefficient of b=3.0, was not viable. It is suggested that selection to improve the alometric traits, condition factor and growth rate is possible with the utilization of the progeny selection, since these traits present low heritability (h2=0.20).