The Yomiuri Shimbun
Crinoids on the seafloor 9,000 meters below sea level
A colony of crinoids–deep-sea animals known as a sea lilies–has been found on the seabed about 9,000 meters below sea level in the Izu-Ogasawara oceanic trench in the Pacific Ocean, according to a group of experts that reported its findings in a scientific journal.
The discovery was made when a research team comprising experts from Tokyo University and Tsukuba University analyzed photographs and video images taken in December 1999 by the Kaiko unmanned deep-sea research vehicle belonging to the Japan Agency for Marine-Earth Scientific and Technology. The team published its findings in Zoological Science magazine.
Although crinoids are commonly called sea lilies, they are marine animals belonging to the echinoderm family, which includes sea urchins and starfish. The area where the colony was found is believed to be the world’s deepest habitat for the species.
The research team confirmed the presence of many sea lilies in the photographs and video images. The sea lilies they identified have stalks about 13 centimeters long and arms about 10 centimeters long that resemble flower petals. They appeared to belong to one of the Bourgueticrinida varieties of crinoid that live in deep waters.
Waters more than 6,000 meters below sea level are called the hadopelagic zone–a dark, cold world exposed to hydraulic pressure several hundred times that of atmospheric pressure. As the place where the sea lilies were found is nearly the deepest part of the Izu-Ogasawara trench, the latest findings suggest such areas might contain abundant organic material that serve as food, according to the research team.
“It’s possible there are similar colonies of sea lilies on deep-sea floors that haven’t been researched yet,” a member of the team said.
Yomiuri Shimbun (Jul. 14, 2009)
)
NATURE IN JAPAN 