Aquaculture: something fishy is going on!
David Murray
Triploid Atlantic salmon
Introduction
• Farmed fish are an incredibly popular part of the global food market
• Aquaculture supplies 16% of all consumed animal protein
• Population expected to rise to 9 billion by 2050 Tacon and Metian, 2015. Aqu.
Introduction
• Aquaculture has a number of bottlenecks preventing its expansion
• Accidental escapes of farmed fish into the wild is a major problem for the industry
• Triploid fish may solve many problems for aquaculture
Impacts of farmed fish escapes
“Wild Atlantic salmon populations are conspecific with farmed salmon, and therefore
susceptible to genetic effects from interbreeding”
Impacts of farmed fish escapes
Farmed
Wild
• Both fish are 18 months old
AquaBounty Technologies®
Triploidy: What is that?
• Organisms containing three sets of chromosomes
Haploid Diploid Triploid
Triploid fish: What are they?
• Triploidy has been successful induced in multiple farmed species
• Impairs reproductive maturation and/or causes infertility
Rainbow trout Blue tilapia
Triploid fish: How are they made? • Pressure or temperature shock and chemicals
can be used to induce triploidy
Meiosis I Meiosis I division
Shock
PB1 PB2 Meiosis II division
Fertilisation
Triploid fish: What are they?
• However, polyploidy can be spontaneous and occurs in naturally producing fertile populations
Piferrer et al., 2009. Aqu.
Methods
Diploid Triploid
Preliminary work on salmon sterility
• Sperm concentrations: diploid vs triploid
Preliminary work on salmon sterility
? Triploid
Diploid
Conclusions (so far)
• No reproductively active triploid salmon.
• However even some diploid salmon were not mature yet.
• Triploids will need to be checked again next year.
Diploid vs Triploid: nutritional sustainability?
“Sustainable feed ingredients has resulted in a decrease in
the nutritional value of farmed salmon”
Sprague et al., 2016. Sci. Reports
Introduction
• Alternative feed ingredients lack essential nutrients
• Previous work has shown that physiology may enhance dietary nutrition
Energetics of Reproduction
Preliminary work
Juvenile Adult
Tocher et al., 2015. Sci. Rep.
Onset of gonadal development
Triploidy and Sustainability
Planned Work
• Comparison of muscle tissue biochemistry between triploid and diploid Atlantic salmon
• Does triploid inhibition of gonadal tissue
provide more nutrients to somatic tissues ?
Conclusions
• Aquaculture provides good nutrition at cheap prices
• Triploidy salmon can benefit conservation of wild fish populations.
• Triploidy may also improve the sustainability of aquaculture.
Thank you
Kainz Research Group University of Vienna Gage Research Group
University of East Anglia
Ims NINA Forskningsstasjon
