Current Research
Visualization of Flow Through Shark Spiral Intestines
We are exploring shark spiral intestine morphologies as mechanisms to produce one-way flow without the use of mechanical parts, which could have a multitude of practical industrial purposes (i.e. drainage, plumbing, water treatment, etc.). Using the CT scan reconstructions from my previous work (see publications page), we will print 3D models of the four different spiral morphologies. These models will be used to conduct particle image velocimetry (PIV) experiments at the Friday Harbor Lab research facilities during the Summer of 2022. This will allow us to understand if spiral intestines are indeed acting similarly to Tesla valves and will allow us to quantify the flow dynamics. |
The Pervasiveness of Microplastic Contamination in Commercial Fishes
We are investigating the prevalence of microplastic contamination in two important commercial fish species: the California Halibut (Paralichthys californicus) and the Pacific (Northern) Anchovy (Engraulis mordax). Using individuals caught from the southern California Bight, we will determine the types and sizes of MPs found in their tissues (digestive tract, liver, and muscle). These fishes are part of a natural southern California marine food web and will eventually be the focus of a larger study to investigate how MP ingestion and trophic transfer conveys physical MP particles and fibers, plastic-associated toxicants, and microbes. |
The Effects of Microplastic Ingestion on Zebrafish Physiology
This project is being lead by Master's student William Nguyen. He is using zebrafish as a model organism to understand how various amounts of microplastic ingestion can impact growth, fecundity, and digestive health. This work is just getting started so stay tuned for future updates! |
Postdoctoral Research
The Ingestion of Microplastics by Zooplankton in Southern California.
Organisms have been shown to consume microplastics across trophic levels, and therefore, there is the potential for bioaccumulation of these particles. Zooplankton is a critically important food source for many secondary consumers. Currently, there is limited information regarding the ingestion of microplastics by zooplankton in southern California; a densely populated area with the potential for high quantities of microplastic pollution, as well as an important supplier of commercial fisheries. In collaboration with Dr. Misty Paig-Tran, I categorized the types and quantities of microplastic ingested by important zooplankton foundation species, as well as those microplastics present in surface waters, through field surveys in multiple different environments within the southern California Bight. |
PhD Research
The Resource Acquisition Strategies of Seagrass-eating Bonnethead Sharks
For my thesis work at UCI I am interested in bonnethead shark energy acquisition strategies. Specifically, how these sharks are capable of digesting seagrass. Sharks, which are uniformly carnivorous, have guts optimized for digesting a high-protein diet. Herbivores, on the other hand, face the difficulty of digesting foods that are low in protein and lipid, and are sheathed in rigid cell walls. Interestingly, the bonnethead shark is known to consume copious amounts of seagrass as juveniles, yet maintains a gut largely reflective of its carnivorous ancestry. Hence, in comparison to other sharks, juvenile bonnethead sharks may have adjusted their digestive strategy to utilize a seagrass diet. To see a video of a bonnethead shark eating a seagrass diet in the lab, click here! See my publications page for a PDF of a paper related to this work. |
3D reconstruction of S. suckleyi spiral intestine by Leigh
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The Function of the Spiral Intestine in Elasmobranchs
This project quantifies flow rate through the spiral intestines of Squalus suckleyi, Sphyrna tiburo, Sphyrna lewini, and Carcharhinus limbatus, measures the contraction rate of the intestinal smooth muscle of S. suckleyi, and provides the first 3D images of spiral intestines for S. suckleyi, Daysiatis say, Rhinoptera bonasus, and Sphyrna tiburo. This investigation provides the first quantification of the functional morphology of the spiral intestine and opens the door to using 3D morphometrics to examine the function of the gastrointestinal tract of fishes and sharks. This project was performed at Friday Harbor Labs as part of the Fish Functional Morphology course and is being continued the German Lab at UCI. |
The Role of Diet Type on the Gut Size and Function of Zebrafish
The aim of this project is to observe how a fish evolves the ability to make a living on a low-quality diet. Through experimental evolution, we seek to understand how three different diets (high-protein, low-fiber; moderate-protein, moderate-fiber; and low-protein, high-fiber) play a role in the gut size and function of Danio rerio (zebrafish) at the individual level and across generations. Here, we used dissections, digestive enzyme assays, and histological techniques to evaluate the physiological and morphological changes of the digestive tract of the zebrafish in response to the experimental diets in the parental generation. See my publications page for a PDF of a paper related to this work. |
Undergraduate research
Pmm1 rescues Pmm2 deficiency in a PMM2-CDG zebrafish model
As a research technician in the biology lab of Drs. Richard and Heather Steet at the University of Georgia, I used zebrafish as a model to study pathogenic mechanisms of lysosomal disease. The results of this study will improve enzyme replacement therapy for humans and has the potential to reverse birth defects caused by inherited lysosomal diseases. |
Diel Patterns of Zooplankton Diversity and Abundance in Big Fisherman’s Cove
For six months, I worked as a research assistant for Dr. Karla Heidelberg at the University of Southern California. I began my work during the Summer Undergraduate Research Experience (SURE) based at the Wrigley Institute for Environmental Studies on Catalina Island. During this time, I formulated and carried out a research project that focused on the vertical migration of zooplankton in the local cove and related this migration to chlorophyll levels, zooplankton biomass, and moon phase. I also created a Marine Zooplankton Guide that is currently being used by the Wrigley Institute for research and educational purposes. |
Effects of Temperature on the Health and Associated Microbial Communities of the Gorgonian Corals of Southern California
For the later part of my time with Dr. Heidelberg, my focus switched to studying the effects of temperature changes on the symbiotic relationship between the California Golden Gorgonian, Muricea californica, and their resident microbial communities. |