When he was eight-years-old, Dan Huber could easily respond when asked if he knew what he wanted to be when he grew up.
“A second cousin of mine was attacked by a shark off of the east coast of Florida,” said Huber. “It absolutely intrigued me. Since I was eight years old, I’ve had a tremendous curiosity about sharks.”
This past summer, Huber flew to Australia to work with a Great White Shark specimen. Along with researchers from two Australian universities, the University of New South Wales and the University of New Castle, Huber, an assistant professor of biology at UT, helped create a computer model of the shark’s cranial structure.
A graduate of Duke University, Huber received his Ph.D. from USF, where he worked with renowned shark biologists. He started working at UT in August of 2006.
The researchers from Australia were going through different groups of animals and studying their bite forces. When they found out about Huber’s expertise on the biomechanics of shark feeding, they brought him into the project.
There are three primary goals for the research. First, they hope to generate the most accurate estimates of the bite forces of sharks that anyone has ever done. Second, they want to look at the structure and use of cartilage in shark’s skeletal systems; while most predators near the top of the food chain have skeletons made of bone, sharks’ skeletal systems are entirely cartilage-based. The third aim is a long-term project focused on developing material to protect people and objects from shark bites.
“Sharks bite trans-Atlantic cables in half,” explained Huber. “If we’re going to build materials resistant to their damage, we have to have a starting point.”
The researchers are currently focusing on white, bull and tiger sharks, using an analytical engineering technique known as finite element analysis.
“This analysis is typically used for designing cars and [looking at] how a car crumples when it crashes,” said Huber. “We’re taking it and adapting it to biological systems, like shark heads.”
The trip to Australia gave him the opportunity to work with a complete organism. Since white sharks are internationally protected, it’s nearly impossible to get any morphological specimens with which he can work.
Once they have an animal, the research team takes a high-resolution CT scan of the head. Computer software digitally reconstructs the scan and puts out a 3-D model.
“Once you’ve got it converted, you then go manipulate it with software to apply forces to it,” said Huber. “You make it do different things to simulate feeding behavior. It can give you a good feel for how these structures have evolved to structurally do what they have to do.”
Using a bit of mechanical engineering, the researchers take the forces produced by muscles in the head and the geometry of the whole muscular system to estimate bite forces.
The 29-year-old Long Island native talked excitedly about his work. Huber intends to show how sharks do things with their soft skeleton that most wouldn’t think possible.
“It’s a very interesting thing to us that you can do all these amazing things, like have a tiger shark bite a sea turtle in half,” he said. “It makes a hell of a lot of sense for someone to do something forcefully with a skeleton made of bone. When you punch something with a hand made of bone, it bends and your arm doesn’t. But if it was made of cartilage, the opposite happens. From an evolutionary perspective, we want to look at how you go about life biting sea turtles with a skeleton made of cartilage.”
So far, he has found that their strength comes from strategically placed calcium deposits.
Human bones are made of collagen and calcium, along with some other elements. Early in human development, bones are basically cartilage, and then calcium fills in the space. In sharks, Huber has found a “rind” or “peel” on the outside of the cartilage that has calcium deposits in it.
“In these particular sharks, we find a unique, very strategic placement of calcium reinforcement which is what ultimately leads to them being able to feed like this,” he said.
Huber also theorizes that their skeletons move a lot. Using his previous research with chimaeras, a shark-like cartilaginous fish, Huber thinks cranial movement is key.
“I’m pretty damn sure that whenever this thing takes a bite, its entire cranium bends,” he said. “Which, from an evolutionary standpoint, doesn’t seem like a very effective strategy.”
Despite all of his experience with sharks, Huber is still surprised by some of his findings.
“The tiger, bull and white sharks were all about the same size. What surprised me was how small the white shark’s head is relative to the other animals,” said Huber. “We anticipate that the bull and tiger sharks will have much, much higher bite forces.”
Though the white shark encounter in Australia was widely publicized, Huber also noted his research on a great hammerhead a few years ago.
When a recreational angler caught a 1,280-pound hammerhead in Boca Grande Pass, Huber was able to work with the animal to get bite force estimates.
“I’m a comparative biologist,” he said. “We tend to take our data and compare it to other people’s data to look for examples of things like convergent evolution, which is basically how unrelated organisms do similar things. I’m always looking to compare my data to whatever else.”
Huber’s work has drawn international attention, as he was featured on multiple shows during the Discovery Channel’s “Shark Week.” As his research pushes forward, he is sure to gather more attention.
“His research is pretty cutting-edge work in the animal morphology field and he is highly respected in the shark community,” said Tanya Brunner, a UT junior and Vice President of the Beta Beta Beta biological honors society. “He conducts his work in a precise and thorough manner and it will really advance our understanding of how different feeding mechanisms have evolved in the Elasmos, [the subclass in which sharks are classified].”