Student stares sharks in the mouth and discovers versatility
Sharks may be scary, but they’re clever, too. After all, they’ve managed to remain the top predators since long before the dinosaurs.
Yet scientists are still discovering new things about the fish that made Jaws a blockbuster and audiences cancel their vacations at the beach.
Take URI senior Jason Ramsay of Coventry, who is fascinated by sharks, particularly their mouths. While most of us think of sharks biting and tearing off chunks of their prey, Ramsay recently discovered that at least one kind of shark can not only do that, but it can also flatten its biting teeth, if shellfish is on the dinner menu.
Ramsay presented his findings at the annual meeting of the Society for Integrative and Comparative Biology in January and an article about his work appeared in the Feb. 13 issue of Science magazine.
The story begins one day when Ramsay was assisting Cheryl Wilga, assistant professor of biological sciences. The URI student tossed several local small green crabs into a tank of white spotted bamboo sharks, in place of their usual fare of soft fish and squid. The sharks immediately gobbled up their shelled snacks.
Curiosity may be the mother of invention, but it also proved to be a motivator for Ramsay, a 30-year-old father of three. The URI senior wondered how it was possible that the sharks could eat the crabs.
White spotted bamboo sharks don’t have the typical teeth for eating shellfish. They have pointed teeth, good for grasping and piercing, but not for crushing. Usually only sharks with low, slightly rounded cusps eat shellfish. A quick check of scientific literature revealed that the white spotted bamboo’s sister shark, the gray bamboo, fed on both fish and shellfish, primarily crabs.
Still curious, the URI student who has been attending URI part-time since 1998 dissected a bamboo shark’s head, removing the muscles and then the jaws, but keeping the teeth and ligaments.
On a hunch, he manipulated the teeth and noticed how unusually flexible the ligaments were. Pressing down on a glass slide, he discovered the teeth folded back and became a flat surface without damaging any teeth. When he substituted a crab for the glass, the same thing happened. All of the teeth bent backward, each row overlapping the row behind it. The folded teeth could make a flat surface for crunching a crab’s tough shell. Once Ramsay released the pressure, the shark’s teeth sprang back up.
Ramsay, who works as a maintenance man at Winman Jr. High School in Warwick, plans to continue his research as a doctorate candidate in the fall and has already been approached for post-doctoral work.
Sharks aren’t Ramsay’s only expertise. In addition to being a crackerjack scientist, he is an artist extraordinaire, according to his professor. Ramsay earned an associate’s degree in art from the Community College of Rhode Island. His work includes anatomical illustrations of sharks and their jaws, which adorn the windows of Wilga’s lab.