Effects of morphological traits on body weight and analysis of growth-related genes of Parabramis pekinensis at different ages

Parabramis pekinensis was treated as research object in order to investigate the correlation between morphological traits and body weight. We measured 9 morphological indexes including total length (X(1)), body length (X(2)), body height (X(3)), head length (X(4)), snout length (X(5)), eye diameter (X(6)), eye distance (X(7)), caudal stalk length (X(8)) and caudal stalk height (X(9)). The principal morphological traits affecting body weight were screened out and the regression equation was established. The regression equation of Y1 (age 1 group) shape character (X) and weight (Y) was Y = − 169.183 + 32.544 × (3) + 10.263 × (4) + 15.655 × (7). The regression equation of Y2 (age 2 group) shape character (X) and weight (Y) was Y = − 694.082 + 7.725 × (1) + 72.822 × (3) + 77.023 × (6), the regression equation of Y3 (age 3 group) shape character (X) and weight (Y) was Y = − 1161.512 + 26.062 × (1) + 22.319 × (2)- 107.218 × (5) + 83.901 × (7). Gene expression was consistent with these conclusions. TOR signaling pathway expression raised in Y1 then width increased. And GH-IGF-1 signaling pathway expression raised in Y2 then the length increased. In conclusion, the paper could prove that P. pekinensis showed a growth trend, which was increasing width first and length later. In some sense, the study not only enriched the basic biological data of P. pekinensis, but also provided waiting morphological traits for selective breeding of P. pekinensis artificial breeding in future.