Characterizing variation in life history traits in a model fish system under harvest predation and environmental change
Daniel Okamoto, Professor
Integrative Biology
Applications for Spring 2025 are closed for this project.
Wild fish populations are often subject to high levels of mortality from industrialized human harvest. Harvest mortality, particularly under certain environmental contexts, may have indirect, unpredictable effects on populations' biology beyond simply the removal of individuals from a population. To study these effects, we are using an experimental model system, a fast-reproducing and small livebearing fish, Heterandria formosa. After several generations of simulated harvest under different available food levels, we have observed some changes in life history and reproductive traits. Some of these appear to be heritable, evolutionary changes persisting in descendants of experimental fish. The work for this URAP project would be to perform dissections of the livebearing females' embryos (in fish preserved from the euthanasia during the experiment) to collect data on number, size, and development of offspring produced by females under certain harvest treatments and demographic contexts. Our goal is to better understand how reproductive investment varied across this experiment, and whether such changes were heritable, or plastic environmental responses. Other directions for student work as a part of this project include assisting with analysis of next-generation sequencing data obtained from fish at the beginning and end of the experiment. Additionally, dissection work may include dissecting for and obtaining data on not just embryos but fish otoliths ("ear stones") as well. This may yield age data for individual fish, which would help with reconstructing the growth rates of fish under different experimental treatments.
Role: Students will be trained to perform fish Dissection, microscopy, imaging, laboratory analysis, and data analysis and perform basic scientific writing and synthesis.
Qualifications: Basic laboratory skills, proficiency in basic computing, and strong writing skills required.
Day-to-day supervisor for this project: Matthew Schumm, Ph.D. candidate
Hours: to be negotiated
Biological & Health Sciences Environmental Issues