Effect of Different Dietary Levels of Protein on Growth Performance of Penaeus monodon Families

The spotted scat (Scatophagus argus) is an economically important farm fish species found in Southeast China.Production of all-female spotted scat population with superior growth traits can significantly increase farmer's benefits due to its sexual dimorphism in growth.Herein, the sex ratio and differences in morphometric traits were observed between females and males in a full-sib population of S. argus.Then the correlation between these traits and their effects on body weight (BW) was analyzed.The results showed significant growth differences between males and females.The correlation coefficient between BW and the other 13 traits reached a very significant level, and the strongest correlation was observed in the body height (BH) (male) and body length (BL) (female).In females, BL, body thickness (BT), head length (HL), and BH had a significant and direct effect on BW.The determination coefficients of traits BL, BT, BH, and HL to BW were 0.163, 0.159, 0.057, and 0.018, respectively with the total value being 0.928.In males, the determination coefficients of six traits to BW were 0.124 (BH), 0.192 (BT), 0.053 (BL), 0.018 (OL), 0.0088 (HL), and 0.0092 (PA), with the total value being 0.855.Moreover, two bestfit linear regression equations were constructed in females and males respectively.This knowledge will provide useful and valuable information in better understanding of the differences between both sexes, relationships between morphometric traits, and selective breeding of S.argus.These models might also provide theoretical support for the indirect selection of traits that are difficult to select directly.