Untargeted Metabolomic Serum Profiles of Three Captive Shark Species for the Generation of a Semi-Invasive Chondrichthyes Health Metric

As near-shore shark species experience abrupt die-off events and habitat loss directly resulting from anthropogenic forces, the need for more specialized conservation efforts for coastal dwellers grows critical. Our research project aims to develop a health metric and subsequent preventative health care strategy for Chondrichthyes. The growing field of metabolomics provides a qualitative approach by identifying potential biomarkers in sharks, particularly those in the circulatory system. Sharks in captivity provide an ideal opportunity to study healthy individuals: aquariums maintain long-term shark inhabitants with individual veterinarian records encompassing blood chemistry and pathology reports that span several years. One such organization is the San Diego Birch Aquarium at Scripps in La Jolla which houses several species of Elasmobranches, including leopard (Triakis semifasciata), horn (Heterodontus francisci), and swell (Cephaloscyllium ventriosum) sharks. Untargeted metabolic data sampled from these resident sharks has provided over 9,906 significant (p ≤ 0.05), tentatively identified molecules of interest including imidazole acetaldehyde, pregnenolone, homocarnosine, and bupropion. The presence of sex hormones such as pregnenolone may be indicative of imminent mating events while bupropion, an antidepressant, may reveal pharmaceutical pervasion in an environment resulting from human proximity. Furthermore, blood metabolic profiles belonging to swell and leopard sharks exhibit similarity while horn shark samples are distinct, signifying species-specific metabolites. The field of Chondrichthyes blood metabolite composition is data deficient and possible dysregulation of serum metabolites between shark species is an additional unexplored area of research. These molecules will serve as a foundation for potential indicators of shark health and fitness and will be implemented in the future sampling of wild organisms.