Student Researcher Maddy Uetrecht dives into moon jelly development
Piecing together all the mechanisms involved in jellyfish development is like working on a jigsaw puzzle that contains 24,000 pieces: it’s complicated. The best way to start is by concentrating on one section at a time. This is the exact strategy CMA student researcher Maddy Uetrecht is using to better understand how moon jellies transition from the juvenile star-shaped ephyra phase of development into an adult bell-shaped medusa.
By working with mentor Dr. Janna Nawroth, a postdoctoral research fellow in Dr. John Dabiri’s Biological Propulsion Laboratory at Caltech, Uetrecht designed a research project to determine how thyroxine impacts moon jelly development. “Scientific research indicates that the hormone thyroxine is involved in jellyfish development in some way,” said Nawroth. “Thyroxine is a common regulator of growth and development in many animals, including humans and frogs. The purpose of Maddy’s project is to determine if this is the case for jellyfish as well.”
Uetrecht’s research project tests the following hypothesis: Exposing moon jelly ephyrae to thyroxine for a long period of time will cause ephyrae to stay in the juvenile star-shaped phase longer, but they will still continue to grow larger. In other words, thyroxine should stall development, while still allowing for growth.
To test this hypothesis, Uetrecht is working with three separate groups of moon jelly ephyrae that all started at the same stage of development when the research project commenced. “The first group of ephyrae is being exposed to thyroxine by adding it to the water allowing juvenile moon jellies to absorb extra thyroxine through their skin,” explained Uetrecht. “The second group of ephyrae is being fed brine shrimp that have eaten squid ink, which contains the amino acid tyrosine, a chemical related to thyroxine. And the third group is the control group, which isn’t being exposed to extra thyroxine.”
Uetrecht comes to the Aquarium three times a week to monitor, mesaure and feed the three groups of ephyrae. Nawroth and Uetrecht also touch base about the project via phone and email to discuss if the concentration of thyroxine being used is too much depending on how ephyrae are responding.
Since the research project is in progress, the verdict is still out on how thyroxine impacts moon jelly development. Answering this question could lead to a better understanding of jellyfish development in general, whether there are genes in jellies connected to the thyroxine hormone and how environmental factors influence jelly development.
“Working with student researchers at CMA is really fun. It’s great to see high school students so excited about jellies and science,” said Nawroth. “Also, it’s a win-win because there are so many questions about jellyfish development and I can’t do all the research projects myself. Maddy is helping me answer questions and in the process learning important research techniques. Together, we are getting closer to figuring out one more piece of the jellyfish puzzle.”