Sean Canfield

PhD Candidate
PI: Brian Bowen
Graduate program: Zoology

I study the biogeography of horn sharks (genus Heterodontus), examining their evolution over deep time-scales and looking at contemporary population genetic structure using next-generation sequencing technologies. Other than being completely adorable, these sharks are interesting because they don’t appear to travel very far at all, particularly through the open ocean. That raises all kinds of interesting questions about their evolution (the order Heterodontiformes is about 200 million years old!) and about how their populations are structured (how did they make it to islands, like Santa Catalina Island in California, Guadalupe Island in Mexico, and the Galapagos Islands, and how often do they make that trip?). Answering these questions can tell us a lot about how to develop and implement good conservation strategies for what I call the “lazy” sharks!
I’m currently working on three major projects/questions:
1) Is there hidden species diversity within the Heterodontiformes?
2) How are populations of Heterodontus francisci structured in the eastern Pacific, and what is the spatial scale of isolation between mainland and island populations?
3) What are the relationships between extant species of Heterodontus? How did the Heterodontiformes evolve after originating in what is now Europe, and achieve their current (nearly circumglobal) distribution?
Here’s a link to a YouTube page with some videos from my field-work in 2014 at Catalina Island, CA (credit to Jessica Maxfield):