lunes, 12 de julio de 2010
"Living Fossils" Found in Atlantic
Star of the Deep
Photograph courtesy David Shale
A rare basket star, seen riding on its intricate network of arms, is among a haul of strange and previously unknown deep-sea creatures recently found in the middle of the Atlantic Ocean, scientists announced Tuesday.
Ten potentially new species—including "mountaineering" sea cucumbers and possible "missing links" between invertebrates and backboned animals—were discovered during the six-week expedition.
The voyage, which ended July 3, was the last of the MAR-ECO project, a series of biological surveys of unexplored waters along the Mid-Atlantic Ridge, the underwater mountain range that bisects the Atlantic Ocean from north to south.
Basket stars are types of brittle stars—starfish cousins that use their intricate arms to walk and snare passing prey such as plankton and shrimp, according to MAR-ECO member Imants "Monty" Priede, director of the University of Aberdeen's Oceanlab in the northern United Kingdom.
Swimming Sea Cucumber—New Species?
Sea cucumbers typically move along the seafloor at a snail's pace. But the MAR-ECO team found this surprisingly mobile individual during their recent expedition to the Mid-Atlantic Ridge between Iceland (map) and the Azores islands (map), scientists announced Tuesday.
Monty Priede, of the University of Aberdeen, thinks the unusual athleticism of this specimen—one of the expedition's ten potential new species—allows the animal to move among grazing areas on steep, undersea mountainsides.
"Nobody had seen [sea cucumbers] in such a complicated environment," he said.
Sea Cucumber Mountaineers
Another new variety of swimming sea cucumber was spotted journeying along the Mid-Atlantic Ridge during the recent MAR-ECO expedition.
Deep-sea sea cucumbers are normally found on the ocean floor. But the study team saw several species high on steep slopes of the vast underwater mountain range running the length of the Atlantic Ocean.
"We've always thought of them as slow-crawling animals, but they are actually capable of swimming," marine biologist Monty Priede, said. "This is quite important on the Mid-Atlantic Ridge, because otherwise there's a risk of starving if they get stuck on a ledge somewhere."