Estimates of heritabilities and genetic correlations for growth and gonad traits in the sea urchin Strongylocentrotus intermedius

Abstract

The present study is the ¢rst estimate for the sea urchin, Strongylocentrotus intermedius, of genetic parameters for growth and gonad traits during the entire reproductive period. 2165^5764 sea urchins were sampled from 74 to 120 families at six di¡erent growth stages. Six hundred individuals were sampled from 20 randomly chosen families at harvest. Coe⁄cients of variation for most growth and gonad traits were high (18.08^78.66%) suggesting a good variation foundation for breeding. Point estimate for heritabilities based on the sire components of variance were moderate to high for test height (0.24^0.39), test diameter (0.21^0.48) and body weight (0.16^0.49). Heritabilities of gonad wet weight, gonad index and gonad moisture at harvest were 0.17, 0.41 and 0.50 respectively (moderate or high). Gonad colour parameters, L à (lightness) and a à (redness) have a heritability of 0, while b à (yellowness) and colour di¡erence DE 1 and DE 2 have very similar heritabilities of 0.2, 0.18 and 0.21 respectively. Heritabilities of b-carotene concentration and content were 0.89 and 0.44 respectively. The genetic correlations between the two measured traits ranged from À 0.984 to 0.999. Gonad wet weight, L à , b à , bcarotene concentration and b-carotene content had signi¢cant positive genetic correlations with all the growth traits. However, gonad index, gonad moisture and colour di¡erences DE 1 and DE 2 had signi¢cant negative genetic correlations with growth traits. The present study indicates that growth, gonad yield and most gonad quality traits could be improved by selection with moderate to high potential. Indirect selection should be applied on gonad traits using growth traits as secondary traits. The present study provides important theoretical guidance for future selective breeding programmes for S. intermedius.

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.…”

Correlation of growth-related traits and their effects on body weight of the mud crab (Scylla paramamosain)

“…Studies on phenotypic and genetic relationships among growth-related traits have been reported in many aquaculture species, including pearl oyster (Pinctada martensii; Deng et al, 2008), common carp (Cyprinus carpio; Wang, 2009), small abalone (Haliotis diversicolor; You et al, 2010), Japanese flounder (Paralichthys olivaceus; Tian et al, 2011), and sea urchin (Strongylocentrotus intermedius; Chang et al, 2012). So far, more statistical methods have been employed to estimate the relationships among economically important traits, such as correlation analysis, path analysis, and regression analysis.…”

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

“…Many studies have been conducted on the phenotypic and genetic relationships of growth traits in aquaculture animals, such as pearl oyster (Pinctada martensii) (Deng et al, 2008), common carp (Cyprinus carpio) (Wang, 2009), small abalone (Haliotis diversicolor) (You et al, 2010), Japanese flounder (Paralichthys olivaceus) (Tian et al, 2011), and sea urchin (Strongylocentrotus intermedius) (Chang et al, 2012). Research on S. paramamosain has mainly focused on reproductive performance (Djunaidah et al, 2003;Zeng, 2007), culture biology Ut et al, 2007), functional genes (Rosa et al, 2008;Wang et al, 2012), population genetic diversity (Shu et al, 2011;Ma et al, 2011aMa et al, , 2012, and molecular markers (Ma et al, 2011b,c).…”