Contribution of metabolomics to the taxonomy and systematics of octocorals from the Tropical Eastern Pacific.

Abstract

Octocorals are sessile invertebrates that play a key role in marine habitats, with significant diversity in the Tropical Eastern Pacific, especially in Ecuador's shallow waters. This study focuses on the most representative octocorals within the Marine Protected Area El Pelado, Santa Elena, Ecuador, as a part of a marine biodiscovery project employing an integrative approach. While molecular techniques have advanced, challenges persist in distinguishing closely related species. Octocorals produce a wide range of compounds, characterized by unique chemical structures and diverse biological properties. Therefore, the main objective of this study was to assess the potential of metabolomics and advanced analytical techniques to analyze the metabolome of these organisms, aiming to refine species classification and improve understanding of octocoral systematics in this region. Untargeted metabolomics effectively discriminates 12 octocoral species across five genera: Muricea, Leptogorgia, Pacifigorgia, Psammogorgia, and Heterogorgia, with notable differentiation between species within the genus Muricea, reinforcing its utility as an additional data set for species characterization. Secondary metabolites such as sterols, steroids, and terpenes (furanocembranolides and sesquiterpenes), were identified in Leptogorgia and Muricea. Overall, this method enabled the identification of 11 known species and a potentially new one, Leptogorgia cf. alba, confirming the extreme diversity of this group in the Tropical Eastern Pacific and within the Ecuadorian marine ecosystem. The study highlights the value of metabolomics in octocoral systematics and encourages for its broader application in marine biodiversity research.