Genetic determination of processing traits in the red swamp crayfish, Procambarus clarkii (Girard)

Abstract

The additive genetic correlations of processing traits (two traits, abdominal meat weight and yield) with growth (body weight) and morphometrics (seven traits, chela length, chela width, cephalothorax length, cephalothorax width, abdominal length, abdominal width and abdominal depth) in red swamp crayfish (6 months old) were first estimated within two sexes based upon the additive-dominance genetic model under two rearing environments. Three geographic broodstocks of Procambarus clarkii (Guantan, Dapu and Yanghe) were used. The genetic mating design was incomplete diallel cross, in which three mating combinations (Guantan ♂ × Dapu ♀, Guantan ♂ × Yanghe ♀, and Dapu ♂ × Yanghe ♀) were produced. Path analysis method was then used to ascertain the overall genetic determinations of growth and morphometric traits on processing traits. The objective of this study is to recommend feasible strategy for improvement of processing traits in P. clarkii. The results indicated that body weight was highly positively correlated with processing traits; chela traits were negatively correlated with abdominal meat weight and positively correlated with abdominal meat yield, but very small in magnitude; negative genetic correlations occurred between cephalothorax dimensions and processing traits; abdominal dimensions were positively correlated with processing traits. Upon pursuing indirect selection for processing traits, body weight should be the primary candidate for direct selection, and at the same time smaller cephalothorax or larger abdominal dimensions also should be taken into consideration.