#33 Thumbs Up Weekly_Longest-Lived Animal

This is my new illustration for the children magazine. The article is about the longest-lived animal. I found the information at National Geographic, and post it at here.

A clam dredged from icy Arctic waters is being hailed as the world's longest-lived animal.

Climate researchers at Bangor University in the United Kingdom recently counted 405 annual growth rings in the shells of a quahog clam. The team plucked the mollusk from 262-feet-deep (80-meter-deep) waters off the northern coast of Iceland.

The team is studying growth lines in clam shells as part of a project to understand how the climate has changed over the past thousand years.

Quahog clams are known for their longevity. A 220-year-old taken from American waters in 1982 holds the official Guinness Book of World Records oldest animal title. Unofficially, the record belongs to a 374-year-old Icelandic clam housed in a German museum. The new clam is at least 30 years older, according to the Bangor University team. The animal died when the researchers counted its rings.

Scientists believe the secret to the clams' longevity is a slowed cell-replacement process. But why they age so slowly is unknown. The researchers hope to use their shell studies to reconstruct a record of environmental changes over the past several centuries. Shell growth is related to water temperature, salinity, and food availability, for example.

for more information: http://news.nationalgeographic.com/news/2007/10/071029-oldest-clam.html