Kara Yopak
Who I am
I have been captivated by elasmobranchs for as long as I can remember, and my interest continued from the age of five through undergraduate and graduate school to today. I received my BA in biology (with a specialisation in marine science) from Boston University in 2002 and completed my PhD in sensory neuro-ethology at the University of Auckland in New Zealand in 2007. I later went on to postdoctoral appointments at the University of California San Diego and the University of Western Australia. While I started my PhD intent on studying elasmobranch behaviour, it was in Auckland that I realised very quickly I couldn’t understand behaviour until I understood the brain. But as I dug into the literature, I saw just how many unanswered questions existed about the brain in this group; and a career was born.
My research explores the evolution of the brain in elasmobranchs, particularly how brain size and organisation (how the size and/or cellular complexity of major brain regions) vary, as well as the similarities that exist between elasmobranchs and other vertebrates, including mammals. The lab’s current collection of fish brain tissue includes more than 1,000 specimens (and counting!). Using this tissue, my students and I compare brain variation both within a species and across different species, while also working to understand the potential drivers of these evolutionary differences. We have examined the brains of more than 180 species – from white sharks to reef sharks to deep-sea dogfish – and find that brain morphology correlates with an animal’s ecology, behaviour and life-history traits. Our lab is also interested in how the brain can change throughout the animal’s life, and how parameters such as ecology, diet, rearing environment and anthropogenic change can lead to shifts in brain size and organisation, with cognitive implications.
Where I work
I have been fortunate enough to have a research programme that has taken me to laboratories around the world, from Boston to New Zealand to San Diego to Australia. But I found my home in North Carolina. My lab is based in the Department of Biology and Marine Biology and the Center for Marine Science at the University of North Carolina Wilmington (UNCW) in Wilmington, NC. In the appropriately named UNCW ZoMBiE Lab (Zootomical Morphology of the Brain and its Evolution), we aim to characterise variation of the brain within and across cartilaginous fish, particularly the ways in which variation in brain size, structure and cellular composition underlies complex behaviour and sensory specialisation.
We are North Carolina’s coastal university, giving us access to waters in the western Atlantic. In addition, thanks to an amazing collaborative network of elasmobranch researchers worldwide, tissue has found its way to us from other parts of the USA, as well as most continents around the world. This has really expanded the taxonomic breadth of species we work on, enabling us to ask deeper questions about variation in the brain in this fascinating group of fish.
What I do
This project is possible due to a collaborative effort between my lab and Gregg Poulakis at the Florida Fish and Wildlife Conservation Commission (FWC), where we have been collecting irreplaceable tissue over the past 10 years from incidental mortalities of the Critically Endangered smalltooth sawfish. The goal of this project is to use advanced bio-imaging techniques (magnetic resonance imaging, or MRI) to characterise brain morphology in this species for the first time and identify key shifts in brain organisation throughout life that might identify changes in sensory specification and behaviour in this species. However, this work has become more urgent on account of large, severely neuro-compromised smalltooth sawfish dying at an unprecedented rate in South Florida. We are hoping that our efforts will shed critical light on the neural impairment currently affecting this species in the Florida Keys, an important first step towards recovery.