Growth characteristics and comparative analysis of Yunlong grouper with Epinephelus moara and Zhenzhulongdan grouper

We analyzed the growth characteristics of the hybrids named Yunlong grouper, derived from Epinephelus moara and E. lanceolatus, and in this paper, we conducted the comparison of the growth characteristics among three groupers, including Yunlong grouper, E.moara and the Zhenzhulongdan grouper, which were cultivated in the factory condition. After establishing the family of two kinds of grouper, we were investigate the fertilization rate, normal development rate and malformation rate of Yunlong grouper, and measured the growth characteristics of Yunlong grouper and E. moara during 45-245 days. At the same time, we counted the growth index and survival rates of the Yunlong grouper and Zhenzhulongdan grouper during 2-13 month after hatching, and counted the survival rate in 13 months. We adopted One-Way ANOVA and Multiple Comparative Analysis to compared the growth characteristics, and fitted the growth model by Excel software. The results show that the average fertility rate, normal development rate, deformity rate of Yunlong grouper was 55.5%±26.7%, 33.9%±23.6%, 8.3%±0.9%, respectively. Until 245 days old, the body weight and body length of Yunlong grouper was (316.7±57.3) g, (22.5±1.7) cm, respectively, About E. moara, measured length (16.8±1.3) cm, weight (123.2±30.2) g. Yunlong grouper grew faster than E. moara, the body weight of Yunlong grouper was as 2.6 times as E. moara’s, and the body length was about 1.3 times. The growth curve of Yunlong grouper during 45-245 days old was W=0.039 2L^{2.891 2}(R²=0.986 9), which reveals that Yunlong grouper was at allometric growth state in this phase, E. moara’s growth curve was W=0.025 5L^{3.021 6} (R²=0.990 8), which reveals that it was in lsogony growth pattern in this phase; after 12 months contrast cultivation between Yunlong grouper and Zhenzhulongdan grouper, the result reveals that the survival rate of Yunlong grouper was 97.2%, while Zhenzhulongdan grouper’s was 93.2%-94%, and the body weight and total length of Yunlong grouper was (700.0±247.2) g, (35.3±4.1) cm, respectively. However, the Zhenzhulongdan grouper’s was (28.6±3.5) cm, (550.0±224.8) g, Yunlong grouper’s weight is 1.3 times the weight of Zhenzhulongdan grouper with 1.2 times total length. The result of this study reveals that E. moara (♀) ×E. lanceolatus (♂) is a ideal hybrid combination, and Yunlong grouper has the advantages of fast growth, low deformity rate, and high survival rate, providing the basis for the study of heterosis, and providing scientific basis for the promotion of Yunlong grouper.