Abstract:Seven countable traits and 20 measurable traits of three populations of the hybrid “Epinephelus moara ♀ ´ E. lanceolatus♂” and its parents, E. moara (♀) and E. lanceolatus (♂) were measured, and the comparative analysis of morphological characteristics among the three groups were performed by virtue of three kinds of multivariate statistical analysis methods, including cluster analysis, principal component analysis and discriminant analysis and variance analysis methods. Chi- square test results showed that there was no significant difference in the countable traits among the three grouper populations. The result of cluster analysis revealed that, characters of “E. moara ♀ ´ E. lanceolatus♂” was more similar to E. moara than E. lanceolatus. Six comprehensive indexes reflecting morphological characteristics were constructed by principal component analysis. The contribution rates of the six principal components were 24.585%, 17.985%, 10.410%, 9.970%, 6.542%, and 5.542% respectively, and the cumulative contribution rate of those was 74.945%. There were obvious deviations in morphological characteristics among the three groupers, forming three different groups and hybrids. “E. moara ♀ ´ E. lanceolatus♂” has its own unique morphological features. By discriminant analysis, four morphological characteristics that have the largest contribution to discriminating grouper, X3 (tongue length/head length), X6 (height at withers/body length), X8 (height at caudal peduncle/body length), X14 (ventral fin basal to the front of anal fin basal/body length), were selected to fit the typical discriminant function (F1=21.108X3+38.413X6-97.206X8+2.223X14-6.849, F2=-10.344X3+21.570X6+21.931X8+26.901X14-17.406) and the classification discriminant function (Y1=217.572X3+750.765X6+1425.499X8+413.410X14-336.464, Y2=318.678X3+839.713X6+1020.377X8+358.203X14-319.723 and Y3=258.526X3+672.660X6+1334.033X8 +311.962X14-269.278) that can distinguish the above three groupers, the comprehensive discriminant rate was 96.43%. It can be considered that the four morphological characteristics selected by stepwise discriminant analysis are feasible for the preliminary identification of three groupers. The results of variance analysis showed that the morphological differences of the three groupers reached significant or extremely significant levels in all characteristics except for X11 (The pectoral fin base to the pelvic fin/body length). Among them, there were 14 morphological traits between “E. moara ♀ ´ E. lanceolatus♂” and E. lanceolatus reached extremely significant levels, and 12 morphological traits between “E. moara ♀ ´ E. lanceolatus♂” and E. moara were extremely significant. The results of this study provide biological basic data for the germplasm identification of “E. moara ♀ ´ E. lanceolatus♂”, E. moara and E. lanceolatus.
