First steps on technological and genetic improvement of European abalone ( Haliotis tuberculata) based on investigations in full-sib families

Abstract

The European abalone Haliotis tuberculata is of eco-nomical importance in Europe, and recently in France where most of the consumed abalones re-mained wild animals fished on the coast. Recently, the creation of hatcheries allowed the production of cul-tured animals, and aquaculture is in progress. To optimize selective breeding programs, different stud-ies were performed on adults and on their progenies. First, ten adult families, assumed to be bi-parental and produced in 2007 were analyzed. As these fami-lies were developed at the beginning of the hatchery production, the parentage of the individual necessi-tated to be tested. The progenies parentage assign-ment was done by using eight microsatellite DNA loci. In fine, the heritability was estimated from the analy-sis of variance of seven full-sib families which include from 23 to 27 progenies. Heritability estimate was the higher for length, width and weight (0.37, 0.29 and 0.40 respectively). A high correlation was also shown between these heritable traits which can be useful during animal breeding. Shell color traits were also analyzed, using image treatment procedure. Two traits were selected according to the global color of the shell: red color and hue. The distribution of these traits evidenced a polygenic genetic control of shell color and measure of heritability evidenced a high to medium value for red color (Cr) and Hue (H) (0.33 and 0.20 respectively). No correlation was shown be-tween growth and this parameter. In a second time, juveniles families produced in 2010 were studied from parents issued of the first selection. A correlation be-tween size and density at juvenile stage was estab-lished but a statistical analysis demonstrated, by us-ing density as co-variable a significant effect of family on size. In these conditions, growth is highly heritable (0.74). This study is a first step toward the use of ge-netic markers for selection, but also a step toward the breeding improvement of European abalone.