A sharper look at shark teeth

Editor's note: Every year, hundreds of undergraduates at the University of Delaware pursue research under the guidance of a faculty mentor. Such experiences provided by UD - a nationally recognized research university - can be life-changing, introducing young scholars to a new field, perhaps even the path to a future career, as they uncover new knowledge. These spotlights offer a glimpse into their world.

With rows of long, razor-sharp teeth jutting out from a mouth that never closes, sand tiger sharks inspire awe at marine aquariums worldwide. Despite their fearsome appearance, these sharks are not aggressive to humans. Rather, humans are the sand tiger shark's top predator. It is federally protected in U.S. Atlantic waters and is listed as critically endangered in some parts of its global range.

At the University of Delaware, Caitlin Bailey, a senior majoring in marine science from Chatham, New Jersey, is taking a closer look at this shark's teeth. Her adviser is Jennifer Wyffels, a researcher at Ripley's Aquariums and UD's Center for Bioinformatics and Computational Biology, who received project support from Ripley's Aquariums.

What are you studying and why?

Bailey: Sand tiger sharks are remarkable to me because they are the only documented species of shark that uses in utero sibling cannibalism (adelphophagy) as a reproductive strategy. The first shark to hatch from its egg case (while in the uterus) seeks out and devours its smaller and less fortunate siblings. Gestation lasts approximately 10 months and the surviving embryo grows to nearly a meter in length before birth. Once I learned about this unique and extreme reproductive mode, I was enthralled and wanted to research the species more.