Tide Bite – BIO-INSPIRATION by Cassandra Donatelli

Best,

Dr. Megan Dethier - FHL Director 

BIO-INSPIRATION by Cassandra Donatelli

Friday Harbor Labs is a great place for a biomechanist. Here at the Labs, you can study everything from the complex three-dimensional ways that animals move in water, to the mechanics of different anatomical structures, to bioinspired design and robotics. The Labs are ideal for this type of work for two major reasons: 1) the amazing animals that are native to the area, and 2) the vast array of tools available to study them, from cameras and microscopes to the material testing system and 3D printers. You can walk around the intertidal just outside FHL and see long squiggly prickleback fish burrowing under rocks, clingfish hanging onto slimy surfaces with their awesome modified pelvic fins, and tiny sculpins darting around in crab-filled tidepools – and then take them right up to a lab to study them.

I have been doing research at FHL since the summer of 2013 when I participated in the BLINKS/REU Summer Internship Program after my junior year at the University of Rochester. There, I was majoring in Archaeology, Technology, and Historical Structures (ATHS), an interdisciplinary major combining engineering, geology, and archaeology. For my undergraduate honors thesis, I measured the hydrodynamics of ancient irrigation canals in Peru. Though I loved the tools and techniques associated with ATHS, I wasn’t passionate about the questions. While working at the library one summer, I found myself on the Wikipedia page for comparative biomechanics. After emailing a few professors, including Dr. Adam Summers, I applied for the REU (Research Experiences for Undergraduates) program at FHL and was accepted!

My first summer here, I worked with Dr. Marianne Porter trying to understand how different shaped vertebrae affected body mechanics and swimming kinematics. This was my first time at a field station, and I instantly fell in love with working with and asking questions about animals. I had a lot of fun applying the methods I had learned in engineering to questions about the way fish moved. That summer, with a lot of support and encouragement from Dr. Porter, I decided I wanted to join a biology graduate program. She introduced me to Dr. Eric Tytell at Tufts University, who became my Ph.D. advisor in the fall of 2014. The work I did that summer, along with programming and computational work done at Tufts, additional mechanical testing with Dr. Porter at Florida Atlantic University, and CT scans gathered at FHL (Figure 1), ended up being the second chapter of my dissertation (Donatelli et al. 2021).

Fig. 1: Pholis laeta (Crescent gunnel). Photo (left) and micro computed tomography (CT) scan (bottom right).

The REU experience changed the way I thought about science. All the research I’d participated in before had taken place in either a sterile hospital lab or in an engineering computer lab. Neither of those experiences inspired me to ask questions beyond what I was assigned. My experience at FHL was so much different. The folks running the program, Dr. Vik Iyengar and Dr. Adam Summers, were extremely approachable and would hang out with us outside of research time. They were always willing to give us candid advice on life as an academic. Dr. Porter encouraged me to use my engineering background to my advantage, rather than trying to hide it and fit in as a “traditional” biologist. Dr. Tytell was excited to chat with me as soon as I emailed him, and our first call instantly eased my fears about applying to a Ph.D. program in a biology department without an undergraduate degree in biology. The folks I met through FHL were all so excited about science, and I knew it must be because of the unique, inspiring, and open environment at the Labs.

After my REU, I made a point to return to FHL every summer. The following summer (2014), before starting my Ph.D. at Tufts, I took the FHL Functional Morphology & Ecology of Fishes course taught by Dr. Summers and Dr. Misty Paig-Tran (CSU-Fullerton). During the course, I fell in love with watching fish swim and spent the 5 weeks writing a series of functions in Matlab to automatically analyze videos of elongate fish swimming. This project became the basis for my dissertation (Figure 2). In 2015, I came back to collect the remaining data needed to turn my fish class project into my first dissertation chapter (Donatelli, Summers, and Tytell 2017). In 2016 and 2018, I was a teaching assistant for the fish course and in 2020 and now in 2022, I am one of the instructors. I was a mentor for the REU program in 2017 and 2021.

Fig. 2: I designed a rig to measure the mechanics of fish bodies (A and B) and built an arena to film them swimming (C). After collecting videos, I wrote software to measure their 2D (D) and 3D (E) swimming kinematics.

All these experiences resulted in new collaborations, and most of the students I mentored at FHL presented their work at scientific conferences like the Society for Integrative and Comparative Biology. I worked with Drs. Sarah Hoffman, Samantha Leigh, and Beth Brainerd on the kinematics and hydrodynamics of the Pacific Spiny Dogfish (Squalus sucklei) fins (S.L. Hoffmann et al. 2019) (Figure 3C), Dr. Matt Kolmann, Dr. Janne Pfeiffenberger, and Tessa Peixoto on the mechanics of the Northern Spearnose Poacher (Agonopsis vulsa) armor (Kolmann et al. 2020) (Figure 3A, B), and Dr. Mo Turner on the 3D structure of seastar denticles (Turner and Donatelli 2019) (Figure 3D).

A. One armor plate of the Northern Spearnose Poacher (Agnopsis vulsa). B. Whole body CT scan of A. vulsa (A and B modified from Kolmann et al. 2020). C. Pacific Spiny Dogfish with markings for automated video tracking (modified from Hoffmann et al. 2019). D. CT scan of the leather star Dermasterias imbricata. Fig. 3: A. One armor plate of the Northern Spearnose Poacher (Agnopsis vulsa). B. Whole body CT scan of A. vulsa (A and B modified from Kolmann et al. 2020). C. Pacific Spiny Dogfish with markings for automated video tracking (modified from Hoffmann et al. 2019). D. CT scan of the leather star Dermasterias imbricata.

I recently got a job as an assistant professor in the Fowler School of Engineering at Chapman University in Orange, CA. My lab will continue to work on fish swimming and mechanics with a focus on bio-inspired design and robotics. I am excited to have students from both the School of Engineering and the School of Science and Technology and I plan on bringing them up to Friday Harbor Labs to give them the inspiring experience I had and continue to have here.

Over my summers here I have been supported by the National Science Foundation REU program (2013), the FHL Research Fellowship Endowment (2017), the Steve and Ruth Wainwright Endowed Fellowship (2018), a Company of Biologists travel fellowship (2020), and the Marine Life Endowment Faculty Fellowship (2022).