Characteristics of growth traits and their effects on body weight of G1 individuals in the mud crab (Scylla paramamosain)

Abstract

ABSTRACT. The mud crab (Scylla paramamosain) is considered a potentially important marine crab species for selective breeding. Here, we first examined sex ratio and differences in 16 growth traits between females and males in a G 1 population of S. paramamosain, and we then analyzed the correlation between these growth traits and their effects on body weight (BW). Of these growth traits, nine were significantly different between sexes. In females, the correlation coefficients in all trait pairs ranged from 0.524 to 0.997. The traits carapace length (CL) and distance between lateral spine 2 (DLS2) significantly affected BW directly, with the path coefficients being 1.124 and -0.186, respectively. The determination coefficients of traits CL and DLS2 to BW were 1.263 and 0.035 with the total value being 0.951, indicating that the two traits were the key factors affecting BW. In males, the correlation coefficients in all trait pairs ranged from 0.881 to 0.999. The three traits body Characteristics of growth traits of G 1 specimens in mud crab height (BH), fixed finger height of the claw (FFHC), and meropodite length of pereopod 2 (MLP2) significantly affected BW directly, with the path coefficients being 0.484, 0.300, and 0.225, respectively. The determination coefficients of traits BH, FFHC and MLP2 to BW were 0.234, 0.090 and 0.051, with the total value being 0.967, indicating that these three traits played a key role in affecting BW. Moreover, we constructed two best-fit linear regression equations, which were Y (BW) = 4.969 X 1 (CL) -0.758 X 2 (DLS2) -140.177 and Y (BW) = 3.806 X 1 (BH) + 2.371 X 2 (FFHC) + 1.725 X 3 (MLP2) -123.559 in females and males, respectively.

Mathematical analysis of morphological traits and their effects on body weight in the red crab (Charybdis feriata)

“…In this study, all phenotypic correlation coefficients between each morphological trait and body weight have reached significant or extremely significant level; nevertheless, it does not mean that each morphological trait has important effect on body weight. Similar phenomenon was observed in other animals such as Strongylocentrotus intermedius (Chang et al, 2012) and Scylla paramamosain (Jiang et al, 2014). This phenomenon is possibly because the interference of other variables was not excluded from the analysis.…”

High-Density Genetic Linkage Maps Provide Novel Insights Into ZW/ZZ Sex Determination System and Growth Performance in Mud Crab (Scylla paramamosain)

“…Thus, the development of genetic breeding programs, including marker- and gene-assisted selection are urgently needed to ensure sustainability and genetic variability of cultured mud crab. Attempts have been made to identify the correlation between some economically important growth traits of S. paramamosain such as body size and weight (Jiang et al, 2014), and transcriptome-derived microsatellite markers (Ma et al, 2014). These serve as foundations for further selection of genomic loci or genes related to the traits of interests by the construction of genetic maps and are of utmost importance and relevance to the aquaculture of this species.…”

“…Mud crabs exhibit significant sexual dimorphism, with females displaying higher growth rate and greater body weight compared to their male counterparts of the same size (Jiang et al, 2014; Waiho et al, 2016b). In addition, coupled with the gravid status of the mature females, the commercial value is substantially higher in females than in males.…”

Female-specific SNP markers provide insights into a WZ/ZZ sex determination system for mud crabs Scylla paramamosain, S. tranquebarica and S. serrata with a rapid method for genetic sex identification

“…A major challenge in mud crab aquaculture industry presently is how to develop a set of fast and viable seed production techniques so as to improve supply [36]. Additionally, Scylla paramamosain , one of mud crab species, exhibits significant sexual dimorphism in growth rate and body size, with females growing faster and having higher nutritive value than males [37]. Thus, it is essential to develop sex-linked markers for production of mono-sex breeding, shortening farming duration, as well as understanding the genetic basis of sex determination system [3, 28].…”