Abstract

Greenshell™ mussels (GSM) are a mollusc endemic to New Zealand and are of economic importance to the New Zealand aquaculture industry. The primary focus of the GSM industry is selection for increased meat weight, however, aesthetics also influence marketability. This study focused on pedigree-based estimation of heritabilities and genetic correlations among GSM traits collected during two harvest seasons: standard and winter. Sizes and weights were highly heritable (0.41±0.07 to 0.92±0.09), and highly genetically correlated across traits and seasons (≥0.75±0.07). Meat cover and gonad scores (measures of visual appeal) had lower heritabilities than did size and yield traits (0.08±0.03-0.25±0.05). Under standard conditions, meat cover had a high genetic correlation with gonad condition scores (0.85±0.04). Under winter conditions the relationship between meat cover and gonad scores was negative (-0.52±0.19). Substantial GxE was observed across seasons (meat cover: rg=-0.58±0.16; gonad: rg=0.62±0.11). Progress made from genetic selection to increase meat yield while controlling for the size may be slow, so selecting for traits related to visual appeal may be preferable. Given that production traits are genetically similar across harvest conditions, selection within standard conditions is likely to improve performance in both standard and winter harvests, thereby allowing for an extended harvest period. However, the genetic improvement of visual appeal of the mussels is likely to be influenced by target harvest season.

AS, Hess, KG Dodds, RD Roberts, N King, J Symonds, and SM Clarke

New Zealand Journal of Animal Science and Production, Volume 78, Lincoln, 66-70, 2018