Prof. Talks Hammerheads on National Geographic TV

TAMPA, Fla. (Apr. 1, 2008)Phil Motta wants to know something.

What’s not to like about hammerhead sharks?

Motta, a University of South Florida biology professor and researcher, said he can’t help but appreciate them for their hunting ability, their unusual sensory organs and, most importantly, their unique yet efficient design.

“The hammerheads are unique because they have such bizarre morphological structures,” Motta said. “The question is, why did this head shape evolve and what are the evolutionary selective measures that caused it to evolve?

“It could be related to sensory organs, it could be related to hydrodynamics or it could be related to feeding” he continued. “I’ve seen great hammerheads use their wide head to slam prey to the ground, but I think that’s a secondary thing. That’s probably not why they evolved it.”

Next week, Motta will share his love for these mysterious sea creatures at 10 p.m. Tuesday on Explorer: Shark Superhighway on the National Geographic Channel. Jenny Ewig, an Associate Producer for National Geographic Television, said the show will present information about the migration routes of hammerhead sharks, how they seem to follow “shark superhighway” in their travels. Motta will discuss the feeding and sensory apparatuses in the hammerhead’s head.

Sharks have been on Motta’s mind since his undergraduate days at Duke University. Today, Motta and his six graduate students investigate the feeding biology of sharks and rays.

But the hammerhead has always held a special place for him because of the mystery behind its evolution. His research on hammerheads and other sharks has gotten him national exposure and even several television appearances, including Animal Planet and NBC’s Today Show in February.

“The latest evolutionary work shows that the one with widest head, the wing head in the Pacific, is the most ancestral,” Motta said. “That’s counter to what everybody thought. We know they came from a pointy-headed shark, but then you go to an extremely wide head and they have been shrinking ever since.”

Tampa Bay is home to the great hammerhead, which measures 14 to 15 feet long and weighs more than 1,000 pounds. Though it has been implicated in attacks, Motta stresses that there’s very little to fear from them.

“All of us in the field are veering away from the killer shark image,” he said. “It doesn’t do any good. It just leads to people killing sharks.

“I think the great hammerhead is up there with some of the most aggressive sharks in the world,” Motta said. “But you’re more likely to get struck by lightning in Florida than get killed by sharks. More people die from bee stings than get killed by sharks.”

And there are some benefits from having the sharks in local waters, Motta said. “They’re used for food, but they’re not a sustainable resource,” he said. “Studies on their immune systems shed new light on our immune system. A new antibiotic was isolated from sharks.

"And if you remove these top-level predators, you shift the balance of the ocean,” Motta added. “They eat stingrays. If you remove the sharks, the stingrays that eat shellfish may multiply and they eat the shellfish beds.”

The University of South Florida is among the nation's top 63 public research universities and one of 39 community engaged public universities as designated by the Carnegie Foundation for the Advancement of Teaching. It is one of Florida's top three research universities. USF was awarded more than $300 million in research contracts and grants last year. The University offers 219 degree programs at the undergraduate, graduate, specialty and doctoral levels, including the doctor of medicine. The University has a $1.8 billion annual budget, an annual economic impact of $3.2 billion, and serves more than 45,000 students on campuses in Tampa, St. Petersburg, Sarasota-Manatee and Lakeland. USF is a member of the Big East Athletic Conference.

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