Improving Pacific oyster (Crassostrea gigas) production through selective breeding

• Main Author: Evans, Sanford, 1968-
• Other Authors: Langdon, Christopher J., Fisheries and Wildlife, Oregon State University. Graduate School
• Format: Doctoral or Postdoctoral Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Crassostrea gigas > Genetics; Crassostrea gigas > Breeding; Crassostrea gigas > Growth; Crassostrea gigas; Pacific oyster
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/1v53k0335

Shellfish growers have expressed interest in developing high-yielding oyster strains through selective breeding. This dissertation has three objectives to help determine the effects of genetic and environmental variation on production traits (body weight, survival, and yield) of Pacific oysters grown in the Pacific Northwest. Objective 1: Determine if relative family performance at harvest is influenced by the nursery conditions in which the families are raised. Algal feeding rate during juvenile development was found to affect adult body weight and survival (P<0.01) among outbred families and adult body weight and yield (P<0.029) among inbred families. No significant genotype x nursery environment interactions were found among outcrossed families (P>0.339). Adult body weight and yield were significantly affected by genotype x nursery environment interactions (P<0.019) among inbred families, with rank changes occurring in the most stressful nursery environments. Results suggest differences in nursery feeding regime should not significantly alter relative field performance of outbred oyster families and should not alter relative field performance of inbred families under all but the most stressful juvenile growing conditions. Objective 2: Determine effects of genotype x environment (GxE) interactions on field performance traits of oysters grown in the Pacific Northwest. Average family adult body weight, survival, and yield were all significantly affected by GxE interactions when raised in four dissimilar environments (P<0.01), however, correlations among performance characters across sites were greater than 0 (P<O.05). Indirect selection in a single environment targeting improved yield in all other environments was 48% to 91% as effective as direct selection within each environment separately. Results suggest development of broadly-adapted oyster strains should be possible using a small number of well selected evaluation environments. Objective 3: Determine heritability of adult oyster body ...