Abstract
Diversifying aquaculture species is critical not only for building climate-resilient food systems but also for making more effective use of available water space for food production. In Aotearoa New Zealand, the Australasian snapper (Sparidae: Chrysophrys auratus) is emerging as a strong candidate for both coastal and open ocean aquaculture systems [1]. This promising warm-water species has close relatives—such as the red sea bream in Japan and the gilthead sea bream in the Mediterranean region—that are already well established in international aquaculture markets, underscoring its commercial potential. This talk presents recent genomic and phenotypic innovations underpinning the development of a selective breeding programme for this non-salmonid species
Over the past 20 years, snapper have been bred and trialled in both land-based and ocean-based systems, with selectively bred fifth-generation (F5) fish showing marked improvements in growth, feed conversion ratio (FCR), and survival [2, 3]. Domestication selection [4], high-throughput phenotyping [5]—leveraging computer vision and machine learning—and genomics-based selection [6, 7, 8, 9, 10] have driven these production related gains in performance .
While early breeding efforts prioritised growth performance, the escalating effects of climate change have recently shifted the focus toward enhancing temperature resilience. Snapper are highly thermally sensitive [11]: growth is stimulated at temperatures above 15 °C, stalls below this threshold, and fish begin to lose condition as temperatures approach 10 °C. Optimal growth occurs near 21 °C, underscoring the influence of environmental temperature on aquaculture viability. In the wild, snapper populations in New Zealand are expanding southward into regions that were previously unsuitably cold, likely facilitated by ocean warming [12, 13, 14]. However, the persistence of low winter temperatures in these areas continues to limit further range expansion and poses significant challenges for survival and growth. In response, we have initiated New Zealand’s largest temperature resilience trial (four temperature treatments, each with 4 replicated tanks, starting snapper numbers per tank 200), involving over 3,000 GBS-genotyped snapper reared under four distinct thermal regimes for 12 months. In addition to high-frequency (8-weekly) phenotyping, the trial integrates whole genome SNP data with transcriptomic and epigenomic profiling to uncover the molecular basis of thermal resilience and growth.
Launched in April 2025, this comprehensive study is producing critical data on genotype-by-environment interactions and physiological responses to thermal stress, with the goal of informing selective breeding strategies for climate-adapted aquaculture. I will present first results from this trial alongside data from recent grow-out comparisons between selectively bred and wild-type fish. Together, these findings highlight the potential of snapper as a climate-resilient aquaculture species and underscore the importance of integrating environmental robustness into breeding strategies for future-ready aquaculture systems.
Cited work
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