Targeted Nutritional Metabolomic Analysis of Marine Species (Tursiops truncatus, Phoca vitulina, Otaria flavescens and Pygoscelis papua).

Ecological nutrition aims to unravel the extensive web of nutritional links that drive animals in their interactions with their habitat. Metabolomic profiling of species could increase the knowledge of their ecology, as well as allowing us to better understand the interactions of environment, including distribution, availability of food and fitness of the species, among others. Metabolomic profile is affected by several causes such as nutrition, physiological status, metabolism and species. Thus, the main aim of this work will be to provide, for the first time, values of the nutritional metabolome profile in marine species, as well as to study the differences in the metabolomic profile due to the classification group. To achieve this, blood samples from marine animals (n = 55) were used in this experiment, including Gentoo penguin (Pygoscelis papua), Patagonian sea lion (Otaria flavescens), Harbour seal (Phoca vitulina) and Bottlenose dolphin (Tursiops truncatus). Blood samples were analysed to determine the nutritional metabolites, specifically non-esterified fatty acid (NEFA), glucose, triglyceride, uric acid, cholesterol, albumin, total protein and inorganic phosphorous (iP). Pygoscelis papua exhibited the most statistically significant differences compared to the other groups, showing higher levels of plasma glucose, triglycerides, uric acid, and cholesterol, and lower levels of albumin, total protein, urea, and iP relative to the average values (simple means) observed in the other species. Also, it can be concluded that nutritional metabolome of Tursiops truncatus is different from that of Otaria flavescens, due to the differences in urea and albumin. These results show the potential of metabolomics to elucidate the relationship between metabolism and external factors in species. However, more molecular ecology studies are necessary to deepen the study of the interrelationships between the environment and metabolism, with the aim of including this tool in specific programmes for conservation and biological study.