Growth of juvenile Pseudoplatystoma reticulatum and Pseudoplatystoma spp. in pond

Abstract

The growth of the fish is an important factor that determines the potential of various species for economic exploitation. The aim this work was evaluates the growth juvenile cachara and hybrid grown in pond. Information was collected of weight and morphometric measures during the experimental period. Total length gain, body height gain, body width gain, weight gain, growth index, morphometric ratios and body percentage were calculated. The methodology of generalized linear models was used, considering Gamma distribution and inverse link function. The variances and averages of variables were submitted tests F of the Snedecor and Chi-Square, respectively. The hybrids gained more weight in second and third biometrics, beyond of presented greater total length gain and body percentage. The head size and head width of cacharas were higher in three biometrics. The variances of hybrids were higher in the second and third biometrics. The hybrids presented better performance, but lesser standardization for traits evaluated than pure specie, confirming the need development genetic improvement programs that performs pure species selection for increased commercial production.

Keywords

• Early stage; Morphometric measurements; Weight; Surubim; Variances