(176h) Metabolomics-Based Assessment of Aquatic Animal Health

Veterinary care and monitoring of aquatic animals faces many obvious limitations, from difficulties identifying symptoms to limits on knowledge of the molecular and biochemical indicators of disease. The most common diagnostic approaches include observable phenotypes and traditional clinical chemistry assays, with only the most basic measures in those assays well-characterized for any given species. Metabolomics (system-wide measurement of the levels of small-molecule biochemical intermediates) is a promising, yet underexploited, method to advance our understanding of a variety of species-specific maladies, as well as our ability to monitor and diagnose aquatic animal health. The systems-scale and potentially untargeted nature of metabolomics makes it ideal to identify biomarkers in the understudied area of aquatic animal health, enabling earlier intervention whether in the field or in captivity.

Here, we present our work in two different aquatic animal systems: the bottlenose dolphin (Tursiops truncatus) and the Atlantic salmon (Salmo salar). We have studied the impact of pathogenic infections on each species (lobomycosis and furunculosis, respectively), and of inappetance due to salmon spawning, on the plasma metabolite profiles of the animals using two-dimensional gas chromatography coupled to mass spectrometry.  In each case, we were able to differentiate between treatment and control groups of animals. These studies have provided significant novel biological insights into each system. In lobomycosis-infected dolphins, the accumulation of fatty acids and depletion of specific vitamin metabolites has suggested the existence of a previously-unexpected catabolic state in such animals. Our investigations of the metabolic impacts of spawning-induced inappetance in salmon – including changes in specific classes of fatty acids – suggest a distinct, but not dysfunctional, metabolic state in these animals, consistent with their natural life cycle. Taken together, our results suggest that metabolomics is a powerful tool to monitor, diagnose, and learn about aquatic animal health.