Growth traits research of the breeding group sub 2 generation of large yellow croaker (Larimichthys crocea)

We measured the egg diameter, oil globule diameter and caliber of offspring of two groups of large yellow croaker (Larimichthys crocea), one breeding group and the other casual, and surveyed these offsprings growth traits, based on which the breeding effect was analyzed. The results show that there is no significant difference (P0.05) between breeding offspring（XY-F2）and not breeding（HB-F1）offspring of large yellow croaker in average egg diameter, oil ball diameter and caliber diameter. The curve of body length and body weight and the curve of body weight and age of moon are fitted for the two groups, indicating that body length and weight has a difference in each group, and that body length and weight of XY-F2 are higher than HB-F1 in the later stage. Body length and realized heritability of bodyweight of 2 years old breeding sub 1 generation (XY-F1) are 0.26, 0.18, respectively,while of XY-F2 are 0.029, 0.134, indicating that breeding promotes large yellow croaker cultivation. The results suggest combining family selection and within-family selection for breeding.