Scientist have found new information on the history of the "Hoff Crab," nicknamed for having a hairy chest.
An Oxford University team discovered the crabs are actually newer to the evolutionary chain than previously projected. Researchers believe the crab diversified 40 million years ago.
The reclusive crabs live in extreme environments. They live around hydrothermal vents that heat the water to 380 degrees Celsius and release noxious chemicals. The deep water in the Indian and Southern Oceans has very little oxygen or sunlight.
The Hoff crab's hairy chest is used for feeding; they "farm" bacteria off of their fur with special mouth-parts allowing them to strain out the edible organisms.
Even thought the crabs can survive in unimaginable conditions, they are very sensitive to changes in the oxygen levels of the ocean, often caused by global warming.
"The life of these charismatic crustaceans is a delicate balancing act,"said Nicolai Roterman of Oxford University's Department of Zoology who led the research and nicknamed the Hoff crabs.
"They need oxygen to survive, which is in short supply around the vents, but the bacteria they 'farm' for food depend on chemicals only available near the vents,"he said. "They exist in the narrow zone where the water from the vents and normal seawater mixes; their challenge is to position themselves close enough to the vents to thrive but not so close that they risk suffocating or getting cooked alive."
It was once thought vent-dwelling creatures would be resilient against climate change, but recent studies have suggested otherwise. Most of the vent species only diversified about 55 million years ago. A global climate change around that time greatly reduced oxygen levels in the deep-sea, and may have been to blame.
Researchers believe there is a pattern of vent creatures getting wiped out from climate changes and repopulating only after the conditions have improved.
During periods of global warming circulation to the bottom of deep oceans could decline, causing less oxygen to reach the bottom.
"Yeti crabs and other such creatures may in fact be especially prone to extinction when there is less oxygen available in the deep ocean," Roterman said. "This is because if deep-sea ocean oxygen levels fall, the amount of oxygen available to these animals - which already live in an oxygen-poor environment at the limits of their physiological tolerance - may drop below the minimum level at which they can survive. They would face the stark choice of 'suffocate or starve.'"
