Fish Larvae Galore!

Fish larvae are my jam.

I cut my teeth as a newbie ichthyologist by working as a larval fish taxonomist for an environmental consulting firm. I spent 40 hours per week mostly looking through a microscope and identifying fish larvae collected from the northern Gulf of Mexico. I held that job for three years, and I learned a lot about the taxonomy of the early life history stages of marine fishes. But, after three years, I felt I needed to learn more about the anatomy and ecology of larval fishes, more than what the consulting job was offering. I needed my PhD.

A big reason I made the decision to quit my job and to go study at the Virginia Institute of Marine Science (VIMS) was because my PhD advisor, Eric Hilton, was managing a project monitoring larval fishes moving into Chesapeake Bay. Joining his lab allowed me to do three things. First, Eric is the curator of the Nunnally Ichthyology Collection at VIMS, so I got to learn a thing or two about natural history museums, which was pretty good considering my current position as the Collection's Manager for the Department of Ichthyology at the Natural History Museum of Los Angeles County. Second, Eric is an expert on fish anatomy, so my dissertation project focused on comparative anatomy of fishes. And third, I got to have a leadership role on this project and stay in the world of larval fishes.

For this project (https://www.int-res.com/abstracts/meps/v527/p167-180/), we worked in collaboration with colleagues in Delaware who were doing the same sampling we were doing. Once a week, we would go out at night on an incoming tide and collect triplicate sets of larval fish samples. We also would measure a suite of environmental parameters. By doing this, we had a weekly record of environmental conditions and the larval fish communities in both Chesapeake and Delaware Bays for two full years. That’s a really neat data set and made for a cool comparison. Chesapeake and Delaware Bays are only about 175 kilometers apart, and they are two of the largest estuaries along the Mid Atlantic Bight (MAB). Understanding the diversity and the timing/duration of larval fish entering each bay has big implications for the ecology of the whole MAB.

We found that the two bays transitioned differently throughout the year. Chesapeake Bay featured two seasons: one in summer and another in winter. These seasons were defined in Chesapeake Bay by an abundance of gobies and anchovies in summer, and drums, flounder, and menhaden in winter. Delaware Bay, on the other hand, featured four seasons, corresponding to spring, summer, fall, and winter. Even though the bays are separated by only a short distance, structurally they are quite different.

This project wound up being a cool collaborative experience with several members of Eric’s lab and Tim Targett’s lab in Delaware. Filipe, Eric’s postdoc, handled the heavy lifting on the manuscript preparation, which is great because this project was not directly part of my dissertation research (more on that in future blog posts). Filipe did a lot of the data analyses and writing. My major contribution was to coordinate field sampling at our site in Chesapeake Bay and identify our larvae. Those are the skills I was already pretty good at, so I was more than happy to take on those tasks. By being involved in this research, I got to learn a lot more about the ecology of larval fishes along the MAB, so that was awesome.

Have any cool fish larvae stories? Let me know in the comments below or over on Twitter!