Biodiversity and Biogeography of Deep-Sea Gastropod Mollusks from the Pacific Costa Rica Margin

Abstract

The deep ocean holds a diversity of life that remains to be discovered and described. Marine ecosystems fueled by chemosynthesis, such as hydrothermal vents and hydrocarbon seeps, represent biodiversity hotspots along the ocean floor. Yet, investigations into the diversity, genetic connectivity, and biogeography of life at such ecosystems are still ongoing. The present dissertation explores the diversity and biogeography of deep-sea gastropod mollusks from hydrocarbon seeps at the Pacific Costa Rica Margin to understand what factors lead to the generation and maintenance of novel biodiversity at chemosynthesis-based ecosystems in the ocean. The Pacific Costa Rica Margin was extensively sampled and explored between 2017 and 2019 and yielded an abundance and diversity of marine life. Gastropod mollusks were chosen as the model organisms for this research as they are taxonomically diverse, are found in high abundance, and occur at chemosynthesis-based ecosystems worldwide. Integrating taxonomic, phylogenetic, population genetic, and biogeographic methods, this dissertation contributes new species, occurrence records, genetic data, taxonomic tools, and biogeographic knowledge for deep-sea gastropods. As global biodiversity continues to be threatened by anthropogenic impacts such as overexploitation and climate change, documenting and understanding deep-sea biodiversity and the factors that influence it is of critical importance.