Discrimination of juvenile snapper (Chrysophrys auratus) growth and nutrition via metabolomic GC-MS methods

Many fish species utilise nursery habitats to enhance survival and growth through vulnerable juvenile life stages. Nursery habitats, however, are often threatened by a variety of stressors, and it is likely that some nursery habitats or locations are more degraded than others. If degraded nursery habitats impact juvenile fish growth or other aspects of fish physiology, a tool to detect this would have great utility in prioritising habitat conservation efforts. We assessed the ability of metabolic profiling to discriminate hatchery reared snapper (Chrysophrys auratus) that had differing food availability and growth rates. Metabolomic profiles of snapper from the different sample groups (i.e. different combinations of fast or slow growth rate and high and low food availability) had high levels of discrimination. This difference was largely driven by an unknown metabolite, which we suspect is a dipeptide proline compound. It is unclear if this unknown metabolite was specific to the results of the present study, or may have more generic value as a bio-indicator of nursery habitat quality. The next step is to analyse the metabolomic profiles of juvenile snapper from a gradient of locations with low to high nursery habitat quality and assess the ability of metabolomic methods to discriminate individual fish from across this more realistic setting.This work was supported by the NIWA Coasts and Oceans research programme 3 [Statement of Corporate Intent 2015/16]; and the NIWA Science Capability Development Fund