So how on Earth do you cook THIS? The shrimp that lives in water four times hotter than boiling point



Rimicaris hybisae was found 5,000m beneath the Caribbean sea



A new species of shrimp has been discovered living deeper than any seen before in the world's most extreme deep sea volcanic vents.

British scientists made the discovery while on an expedition to explore boiling undersea springs - which may be hotter than 450C - on the Caribbean seafloor.

Some 5,000 metres down, in a rift in the seafloor, exists a volcanic spring known as a 'black smoker', which fires a jet of mineral-laden water more than a kilometre into the ocean above.



No little discovery: Rimicaris hybisae, the world's deepest known vent shrimp, was found at a depth of 5,000 metres

Hot stuff: Thousands of the newly discovered species of shrimp mass around an oceanic geyser beneath the Cayman Islands, in temperatres in excess of 450C

But despite the extreme conditions, the vents are teeming with thousands of a new species of shrimp that has a light-sensing organ on its back.

The pale shrimp congregate in hordes - up to 2,000 shrimp per square metre - around the six-metre tall mineral spires of the vents.

Lacking normal eyes, the shrimp instead have a light-sensing organ on their backs, which may help them to navigate in the faint glow of deep-sea vents.



The researchers have named the shrimp Rimicaris hybisae, after the deep-sea vehicle that they used to collect them.

Water cannon: One of the 'black smoker' vents, 5,000m down on the Caribbean seafloor, belches a jet of mineral-laden water more than a kilometre into the ocean above

The Cayman shrimp is related to a species called Rimicaris exoculata, found at other deep-sea vents 4,000 kilometres away on the Mid-Atlantic Ridge.

The team was led by marine geochemist Dr Doug Connelly, of the National Oceanography Centre in Southampton, and marine biologist Dr Jon Copley, of the University of Southampton.

During an expedition in April 2010 the scientists used a robot submarine to locate and study the vents at a depth of five kilometres in the Cayman Trough, an undersea trench south of the Cayman Islands.

The vents are gushing hot fluids that are unusually rich in copper, and shooting a jet of mineral-laden water four times higher into the ocean above than other deep-sea vents.



Although the scientists were not able to measure the temperature of the vents directly, these two features indicate that the world's deepest known vents may be hotter than 450C, according to the researchers.



Elsewhere at the Beebe Vent Field, the team saw hundreds of white-tentacled anemones lining cracks where warm water seeps from the sea bed.



Dr Copley said: 'Studying the creatures at these vents, and comparing them with species at other vents around the world will help us to understand how animals disperse and evolve in the deep ocean.'

The researchers also found black smoker vents on the upper slopes of an undersea mountain called Mount Dent which rises nearly three kilometres above the seafloor of the Cayman Trough, but its peak is still more than three kilometres beneath the waves.



Dr Connelly said: 'Finding black smoker vents on Mount Dent was a complete surprise.



'Hot and acidic vents have never been seen in an area like this before, and usually we don't even look for vents in places like this.'



A light in the dark: The vents of Mount Dent are also home to snake-like fish and previously unseen species of snail and a flea-like crustacean called an amphipods

He said: 'Because undersea mountains like Mount Dent may be quite common in the oceans, the discovery suggests that deep-sea vents might be more widespread around the world than previously thought.'

The vents on Mount Dent are also thronged with the new species of shrimp, along with snake-like fish, and previously unseen species of snail and a flea-like crustacean called an amphipod.

Dr Copley said: 'One of the big mysteries of deep-sea vents is how animals are able to disperse from vent field to vent field, crossing the apparently large distances between them.

'But maybe there are more "stepping stones" like these out there than we realised.'

The British expedition that revealed the vents followed a U.S. expedition in November 2009, which detected the plumes of water from deep-sea vents in the Cayman Trough.

A second U.S. expedition is currently using a remotely-operated deep-diving vehicle to investigate the vents further and the British team also plans to return to the Cayman Trough in 2013 with Isis, the National Oceanography Centre's deep-diving remotely operated vehicle, which can work at depths of up to 6,000 metres.