Effects of morphological traits of rice flower carps of two body shapes on body mass

【Objective】To analyze morphological traits of rice flower carps cultured under traditional methods in northern region of Guangdong Province of two body shapes，round shape and long shape and to explore the relationship between the morphological traits and body mass，so as to provide reference for selecting and breeding new rice flower carp varieties based on morphological traits.【Method】Rice flower carps cultured under traditional methods in northern region of Guangdong Province were taken as test material，and they were divided into two populations according to two kinds of body shapes，round shape and long shape. Their growth traits were measured accurately. Path analysis and grey correlation analysis were used to define the effects of nine morphological traits，total length（TTL），body length（BL）， head length（HL），body height（BH），caudal peduncle length（CPL），caudal peduncle height（CPH），tail length （TL），head height（HH），body width（BW）on body mass of 6-month-old rice flower carps of round shape and long shape.【Result】Coefficients of variation of rice flower carps in the round-shape and long-shape populations were 44.51% and 43.90%，respectively，indicating that the body mass had a great breeding selection potential. Mean square test analysis of the growth traits showed that the CPH，BW and body mass traits were not significantly different between the roundshape population and long-shape population（P>0.05），while other growth traits had extremely significant differences（P< 0.01）. Stepwise multiple regression analysis results showed that four morphological traits of BL，CPH，BH and HH functioned in the round-shape population and five morphological traits of BL，BW，BH，HL，and HH functioned in the longshape population. The multiple correlation coefficients（R²）of round-shape and long-shape populations were 0.951，and 0.953，respectively，indicating accuracy in analyzing main morphological traits that influenced body mass. The results of grey correlation analysis showed that the average correlation coefficients of round-shape and long-shape populations were 0.827-0.860 and 0.760-0.803，respectively. Seem from the same morphological traits，mean coefficients related to body mass of the round-shape population were higher than that of the long shape population.【Conclusion】The common morphological traits between the round-shape and long-shape populations were screened through both path analysis and grey correlation analysis：in round-shape population，BL，CPH，BH and HH were the main traits related to body mass；in longshape population，TTL，BW and BH were the main traits related to body mass and the two analysis results were largely consistent.