Characterising Sex-Specific Metabolite Differences in New Zealand Geoduck (Panopea zelandica) Using LC-MS/MS Metabolomics

Geoduck aquaculture is becoming a key component in meeting international market demand, given the natural and regulatory restrictions on wild geoduck supply. Geoduck clams are not sexually dimorphic, making it practically unfeasible to distinguish between males and females prior to a spawning event. To facilitate increased production of geoduck, a better understanding of reproductive biology and associated targeted bio-markers is required. In this study, metabolomics was utilised as a research tool to distinguish between metabolites related to male and female New Zealand geoduck (<i>Panopea zelandica</i>), gill and muscle samples collected from broodstock individuals housed in an experimental hatchery. A total of 17 metabolites were detected, showing significant differences between sexes. The findings indicate that metabolites associated with lipid biosynthesis were increased in female clams to support reproductive functions. An increase in carbohydrate-linked metabolic pathways was detected in male geoduck, arguably to sustain sperm production. Taurine has been reported as a biomarker to distinguish between male and female bivalves in other studies and is confirmed within this study, with significant elevation in male adductor muscle tissue. Moreover, male geoduck had increased purine and pyrimidine biosynthesis, supporting energy needs. This study provides useful sex biomarkers for future breeding strategies of <i>P. zelandica</i>.