A Living Fossil
Rare shark captured on film
|A frilled shark swims in a tank at Awashima Marine Park in Shizuoka, Japan, after being found by a fisherman on January 21, 2007. (Photo: Awashima Marine Park/Getty Images/NewsCom)|
February 7, 2007
A unique species of shark—a frilled shark—was recently captured on film at a marine park in Japan. This species of shark is rarely seen alive, because its home is about 2,000 feet under the sea.
“We believe moving pictures of a live specimen are extremely rare,” said an official at Awashima Marine Park, in the city of Shizuoka, south of Japan’s capital of Tokyo.
It all started when a fisherman noticed an unusual brown creature, with a mouthful of sharp-looking teeth and an eel-like body. The fisherman contacted the staff at the Awashima Marine Park. Staff members brought the five-foot-long creature back to a pool at the facility, where they filmed it swimming.
The fisherman had made a very rare find—a female frilled shark. The shark gets its name from the “frilly” skin surrounding its six gills.
Frilled sharks (Chlamydoselachus anguineus) usually live at depths of 2000 feet. The species is also known as a “living fossil” because it has changed little since prehistoric times.
"The idea of frilled sharks being living fossils is due to their six gill slits, compared to five in so-called modern sharks," explained Alexander. J. Godknecht, chairman of the Shark Foundation, in Zurich, Switzerland.
It is believed that frilled sharks live in the Pacific, Atlantic, and Indian oceans. The sharks eat other fish, such as squid, swallowing them whole. According to Godknecht, scientists learned about the species' eating habits by examining frilled sharks that were found dead in fishing nets.
"The teeth are very pointed and not usable as saws [like the teeth of tiger sharks or white sharks] so they cannot chew their food,“ Godnecht told Scholastic News Online.
With 300 white, razor-sharp teeth and a mouth that is always open, the frill shark’s looks can be pretty frightening! In fact, scientists say it's the “pearly whites” that attract prey to its open mouth.
Unfortunately, the frilled shark discovered in Japan didn’t survive more than a couple of hours. Park officials aren’t sure what caused its death, but suggest the shark may have been sick. Another possibility is that the shark was weakened because it was in shallow waters.
Critical Thinking Question
Read today's news story, and then answer the following question.
A Living Fossil
Why do you think capturing a frilled shark on film would be of interest to scientists?
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Gail Hennessey recently retired from teaching 6th grade social studies in Harpursville, New York. For more information and activity ideas, visit her Web site at http://www.gailhennessey.com/