METABOLOMICS: AN INNOVATIVE AND POWERFUL TOOL FOR AQUACULTURE

Biotechnological applications in aquaculture have grown exponentially in the last decade or two.  Omics approaches, such as genomics, transcriptomics, proteomics and metabolomics provide platforms for considerable research innovation and targeted solution driven applications. One of the more recent omics arrivals to aquaculture is metabolomics - the study of  metabolite profiles to identify biomarkers indicative of physiological responses of living samples (e.g., whole organism, tissues, cells) to environmental or culture conditions.  Because metabolites are most sensitive to environmental changes, they provide information about what is actually happening at the metabolic and physiological level.  In this manner, unexpected problem or risk areas can be identified for further management action.  While the techniques and data analysis of metabolomics-based research still require considerable expertise, rapid developments in analytical platforms, computational capacity and bioinformatics are making it more possible for general scientists to carry out such research.  As a result, recent metabolomics publications in hatchery production, nutrition and diet, disease and immunology, and post-harvest quality control demonstrate the power of this innovative approach within aquaculture.

To illustrate this approach, we report on metabolomics-based studies to address larval production problems (e.g., poor health, inadequate nutrition), which often result from causes that are difficult to identify.  For example, New Zealand Greenshell™ mussel (Perna canaliculus) larvae often experience high intraspecific growth variations, with unexpected batch crashes.  To address this production bottleneck, we investigated metabolite profiles to identify physiological biomarkers indicative of larval quality during hatchery production.  In-depth analysis of these biomarkers were used to identify potential biochemical pathways involvement in larval performance.  A similar metabolomics approach was used to identify health biomarkers of OsHv1 virus susceptibility and resistance by oyster (Crassostrea gigas) larvae under different viral exposure conditions.

These studies illustrate not only how metabolomics can be used to assess mollusc larval quality, but they signal the potential to generate predictive models of larval performance.  It is envisaged that future research will eventually lead to easy-to-use tool kits to evaluate the physiological state of larvae throughout the rearing process.