Crustaceans have some of the largest genome sizes among animals. For example, some shrimp have genomes that are over five times larger than the human genome! However, the causes and consequences of large genomes in crustaceans is relatively understudied. SU Biology faculty Kristin Hultgren, along with undergraduate Jeremy Bjelajac (SU Biology ‘18) and other co-authors, just published a paper in the Journal of Evolutionary Biology examining how genome size in snapping shrimps is related to reproductive traits, such as egg size and larval development. They found that species with larger genomes tend to have larger eggs, and larger eggs are associated with abbreviated larval development—a reproductive feature that can strongly affect the ecology and demographics of a species. As a summer undergraduate researcher at Seattle U, Jeremy Bjelajac worked on measuring genome size in these shrimp using flow cytometry. He is currently pursuing his PhD in the Institute for Stem Cell Biology and Regenerative Medicine at Stanford University.

Alpheus immaculatus – a snapping shrimp that lives symbiotically in sea anemones in the Caribbean—has an estimated genome size of 18.2 pg (in comparison, the human genome is only ~3.3. pg).