Cumaceans, known as comma shrimp

My lab studies cumaceans, small critters that are commonly known as comma shrimp. They are too small for shrimp cocktail, but they do sometimes look like commas! We are going to the Antarctic to collect cumaceans to find out a variety of different things. The first and most basic question is how many species are there? Cumaceans are small, and very few people study them, so we don’t even know how many species there are around the Antarctic. Cumaceans don’t move around very much, they are not very good swimmers, and there is not a larval stage in the life cycle so it’s hard for them to move long distances. Thus, it is likely that each area of the Antarctic has different species, even if they look pretty similar, a phenomenon known as cryptic speciation. My graduate student, Victoria Vandersommen, is working on Antarctic cumacean diversity.
             
Victoria did undergraduate research with me on determining if cumaceans have a microbiome while completing her degree in Environmental Studies. She is currently a ship captain and tour guide on the vessel Discovery in Prince William Sound, a very scenic part of Alaska, and started a Master’s in Biology in the fall of 2022. For her project on circum-Antarctic cumacean diversity, we have samples from 2020 from the Western Antarctic Peninsula region, we will be collecting samples in the East Antarctic very soon, and from the Ross Sea in the future, so we will have samples from all around Antarctica for her project.

I did my BA and MS at University of California, Santa Cruz, and a PhD in Oceanography at the University of Maine Orono, and I am currently a Professor of Biological Sciences at the University of Alaska Anchorage. My biological research that brings me to Antarctica is exploring cumaceans as a model system to explore invertebrate adaptations to the changing Antarctic. This project will leverage integrative taxonomy, functional, comparative and evolutionary genomics, and phylogenetic comparative methods to understand the true diversity of Cumacea in the Antarctic, identify genes and gene families experiencing expansions, selection, or significant differential expression, generate a broadly sampled and robust phylogenetic framework for Cumacea based on transcriptomes and genomes, and explore rates and timing of diversification in Antarctic cumaceans. The project will contribute to understanding of gene gain/loss, positive selection, and differential gene expression as a function of adaptation of organisms to Antarctic habitats. Phylogenomic analyses will provide a robust phylogenetic framework for Southern Ocean Cumacea. My other current areas of research interest are shorebird diets and biology education.

Dr. Sarah Gerken
University of Alaska Anchorage