‘EXTREME DEEP’ CREATURES LIVE IN A WORLD ALL THEIR OWN
Few people will ever have the privilege of diving nearly 3 miles to the ocean floor to view the unique life forms there. EXTREME DEEP: Mission to the Abyss sponsored by John Hancock Financial Services and Discovery Channel is as close as one can get. Presented by Evergreen Exhibitions in collaboration with Woods Hole Oceanographic Institution (WHOI), EXTREME DEEP presents a total immersion environment in which visitors get a firsthand look at the life forms which, until recently, few even thought existed.
The exhibit offers museum visitors an up-close look at the remarkable creatures found during the exploration dives of the deep-sea submersible Alvin and other research vehicles operated by WHOI.
In 1977 scientists in Alvin got their first look at hydrothermal vents and the complex biological communities they support. Seawater circulates into cracks and fissures at vent sites, encountering heat emanating from the earth’s molten core. This warm water circulates back onto the ocean floor, creating a life-supporting temperature gradient at a depth where the waters typically are near freezing. EXTREME DEEP depicts creatures that live in proximity to the warmth of the vents. At these depths, where light doesn’t penetrate, faunae rely on a process called chemosynthesis, in which they and bacteria living on them process chemicals including hydrogen sulfide for their food.
More than 500 new life forms have been discovered at the vent sites, all of them new to science. In EXTREME DEEP visitors walk through the re-created vent site for a close-up look at deep-sea life–without the water. They will see:
Marianactis bythios is a white sea anemone with tapering, pointed tentacles. They grow up to 125 mm, or about 5 inches, long. They cling to rocks in clusters around the deep-sea vents.
Paralvinella palmiformis is most commonly found partially coiled around tubeworms or on the surface of sulfide mineral deposits near the Juan de Fuca Ridge and other nearby sites off the coast of Washington state. Segmented with a tapered body, it grows up to 80 mm (about 3.2 inches) long.
Alvinella pompejana, or Pompeii worm, grows up to 150 mm (about 6 inches) long. It hosts bacteria on its body, which feeds the worms. These worms typically live in large honeycomb-like tube masses around vent openings and on the walls of white smokers, and have also been seen on the sulphide chimney walls of black smokers. It thrives at temperatures ranging from 50o F to 176o F.
Thermarces cerberus, or vent fish, are whitish or pinkish and have no scales. Also known as eelpout fish, they are among the few fish seen at deep-sea vents. This fish lives at vents on the East Pacific Rise, feeding on small invertebrates.
Tevnia jerichonana, or Jericho worm, forms clusters on rocks in zones of diffuse venting, where temperatures range from 41o F to 86o F. It is an early colonizer of new vent sites. White or gold/brown and opaque, its sinuous tubes can be as long as 350 mm or 14 inches. It receives nutrition via chemosynthesis.
Riftia pachyptila, or tubeworms, can grow up to 1.5 m, or nearly 5 feet long. A tough, flexible protein tube protects its soft body. The worm extends its red, hemoglobin-rich gills out the top of the tube to absorb oxygen and carbon dioxide from the water, and retracts to avoid danger. Tubular, they form clusters on rocks in zones of diffuse venting, living in temperatures of 41o F to 86o F. Bacteria living in the tubeworm’s tissues “eat” hydrogen sulfide, then convert the chemical’s energy to food, which they share with their tubeworm hosts.
Calyptogena magnifica, or giant white clam, is found in clusters of hundreds around the vents, where they’re bathed in hydrogen sulfide. Bacteria in the clams’ gills use the chemical to make food for themselves and their clam hosts. Their shells are as long as 26.3 cm or 10 inches, about the size of a dinner plate.
Bathymodiolus themophilus, or mussels, secrete threads for attaching to rocks and they filter food from the water like the mussels of shallower waters. However, these deep-sea mussels rely on bacteria living in their gills to produce food. Their shells grow to nearly 18 cm or 5 inches in length.
Jellyfish aren’t fish at all. More related to corals, they are 94 percent water and 6 percent nerves, tissue and stinging cells. They don’t have a heart, brain or bones. These fragile creatures have floated the seas for 650 million years. They account for most of the biomass in the ocean. They are found in “midwater” regions of the ocean.
Rimicaris exoculata, or shrimp, swarm by the thousands on black-smoker chimneys at some North Atlantic sites. Two inches long with no eyes, these shrimp scrape the chimney sides with their claws to eat bacteria and sulfide minerals. Unlike their shallow-water cousins, these shrimp tasted like rotten eggs when scientists cooked and sampled them.
Munipopsis subsquamosa, or squat lobster, lives in great abundance in peripheral regions of vent fields on the East Pacific Rise. One curious behavior of this crustacean is its tendency to turn in the same direction as those it is clustered with, presumably in response to some current-borne signal.
Bythograea thermydron, or crab, is a common vent-site resident and often the first to colonize a new vent. At first they feed on mats of bacteria and, as worms and other organisms move in, they are added to the crabs’ menu. The carapace, or body, of these crabs grows to just longer than 2 inches. A predator and scavenger, these creatures take bait in traps.
EXTREME DEEP, designed for ages 6 and older, introduces geology, history, biology, chemistry, exploration and the critical role that technology plays in understanding our world and its future.
EXTREME DEEP will crisscross the country, showing in the nation’s finest science centers and museums for five years.
All releases & terrific photos available electronically at Evergreen Exhibitions.