Growth and morphological characteristics comparison of northern large-mouth bass, Florida largemouth bass and their reciprocal hybrids

Abstract

Based on northern largemouth bass and florida largemouth bass, four populations including selfing of N(Micropterus salmoides salmoides ♀×M. s. salmoides♂) and F(M. s. floridanus ♀×M. s. flori-danus♂), direct cross NF(M. s. salmoides♀×M. s. floridanus♂) and FN(M. s. floridanus♀×M. s. sal-moides♂) were established. Further comparative analysis of growth and morphological characteristics were carried out between parents and their reciprocal hybrids. The results were as follows. The growth rates had no difference between N, NF and FN on 152nd day. After 152 days the northern largemouth bass grew more rapidly than two hybrids. As meristic characters, the numbers of soft ray of pelvic, spine of anal fin, gill raker and vertebra were consistent in these four populations, and the chi-square analysis of meristic characters showed highly significant differences between parents and hybrids in soft ray of dorsal, soft ray of pectoral, soft ray of anal fin, soft ray of tail fin, scales above lateral line and scales below lateral line. The results of cluster analysis have revealed that the morph metric characters of N and F were much closer, the same to the reciprocal hybrids groups. Three principal components with accumulative variance per-centage 71.44% were summarized in principal component analysis. The principal components 1, 2 and 3 reflected the morphological variations of frame, head and caudal peduncle, with the variance percentage being 54.90%, 11.20% and 5.33%. In discriminant analysis, 11 parameters were selected from 35 measured parameters to establish discriminant functioned of the populations. Discriminant accuracy was 83.90%—100.00%. This study would be beneficial to the identification, breeding and aquaculture of largemouth bass.