Genetic Analysis for Absolute and Relative Growth of Body Weight and Main Morphological Traits in Chinese Mitten Crab, Eriocheir sinensis

Abstract

AbstractTo estimate genetic parameters for main growth traits measured in different scales in Chinese mitten crab, a total of 1600 and 4857 individuals from 20 families were observed for body weight, body length, body width, and body depth at two measuring periods. With multivariate animal models for absolute growth, the heritabilities for these growth traits were estimated to be low and moderate at the sampling and harvesting periods, respectively, while pairwise ratios between body length, width, and depth indicated low inheritance. This suggested that the shape of the crabs can be genetically improved with family selection. Genetic correlations, which all exceeded 0.68, were consistently higher in the harvesting period than in the sampling period. A random regression model was constructed to genetically analyze multiple allometries that were used to define the relative growths of these growth traits. As a result, the heritabilities for the allometry scalings were estimated as 0.893, 0.909, and 0.488 of body length, depth, and width to body weight, respectively. Genetic correlations of the allometry scalings, which ranged from −0.975 to 0.097, considerably differed among three morphological traits. According to the genetic parameters of the allometry scalings of morphological traits to body weight, synchronous growth of body shape with body weight might be genetically regulated through selective breeding for their relative growths.