UC Berkeley

Most of the deep sea is characterized by low productivity and low biomass, however there is a patchy distribution of unique habitats that support specialist communities and high biomass. These habitats include hydrothermal vents and cold seeps; geological features that provide reduced compounds like sulfide and methane to fuel chemosynthesis, an alternate form of primary production to photosynthesis. Organic falls like whale carcasses and wood support related but distinct communities of scavengers, grazers, filter feeders, and extreme specialists.

This dissertation examines multiple levels of specialization to deep-sea reducing environments to address the following questions:

1. Is there a common evolutionary path toward specialization in reducing habitats?

2. How have lineages modified their anatomy to specialize in deep-sea habitats?

3. How does variation in sunken wood influence community assembly?

To address the first question, I used a supertree of the Gastropoda, one of the most diverse animal groups in reducing habitats, to ask whether lineages followed similar trajectories toward becoming specialists in these ecosystems. For the second question, I focused on a lineage of limpets (Lepetellidae) that has only been found living on empty Hyalinoecia polychaete tubes, and made hypotheses about how they utilize their substrate based on a detailed 3D reconstruction of the anatomy of Lepetella sierra. The third question focuses on how variation in the substrate can influence diversity and community assembly, particularly in wood fall communities colonizing experimental wood fall substrates of ten different types over the course of two years at 3200m near Monterey, CA. Through the course of exploring these three questions, I have developed collaborations, learned new skills, and contributed new data and perspectives on deep-sea reducing environments.