Great white sharks have started filtering back into Massachusetts waters. Researchers are pretty sure food is what brings them here, but it’s hard to know for sure what sharks are thinking.
Kara Yopak is an assistant professor at UNC Wilmington, where she studies shark brains. She’s spent much of her career trying to get inside the heads of sharks, literally.
When she was a student, there was one paper that really piqued her interest. It was from the 1970s that looked at brain-weight to body-weight ratios in twelve sharks. It showed that sharks had ratios that are comparable to birds and mammals, which was shocking to Yopak because sharks are usually thought of as pre-programmed eating machines.
One of those widely thought of "eating machines" is the great white shark, whose brain has a distinctive look.
“They don’t look like miniature human brains – they’re elongated, sort of like a spark plug,” Yopak said.
The parts of the brain that are enlarged are tied with “motor control, vision, and smell,” which makes sense when you think about how great whites hunt.
Shark brains come in many shapes and sizes. Great white sharks are different than deep sea shark brains for instance. Deep sea shark brains have a large region for olfaction and an exceptionally large region for electroreception.
“This reflects specialization of non-visual senses of deep, dark environments,” Yopak said.
Yopak’s lab, the “ZoMBiE” lab currently houses more than four-hundred brains from one-hundred-and-eighty different species of sharks, including a two-headed shark embryo.
“If you lined up all 180 brains on a table, you could group them together,” Yopak said. "You’d group together species that live in similar places and do similar things."
The ability to study shark brains has been a positive for the species.
“It’s great to have a broad data set," she said. "We can start to be predictive about behavior of species whose behavior we couldn't study otherwise."