New sea creatures: It's life, but not as we know it

The species found by University of Aberdeen researchers include brainless sea worms, an unusually fast-swimming sea cucumber and an elaborate deep-sea starfish.

The sea worms, known as enteropneust acorn worms, observed and captured by the team are believed to be close to the missing evolutionary link between animals with and without backbones.

And the scientists say the six-week trip that revealed the abundance of previously unknown creatures has revolutionised their thinking about deep-sea life in the Atlantic Ocean.

Professor Monty Priede, director of the University of Aberdeen's Oceanlab, who led the expedition, spoke to The Scotsman yesterday fresh from his trip aboard state-of-the-art survey vessel the RRS James Cook.

He said there was such an abundance of species in the deeps of the ocean that he felt like "(Charles] Darwin landing in Patagonia". "We have a massive amount of samples, with thousands captured and many thousands of images new to science," he said. "It will take many years to analyse."

The bizarre and colourful species were spotted living on the slopes and valleys of undersea mountains that make up two sections of the sub-sea Mid-Atlantic Ridge between Iceland and the Azores.

A remotely operated vehicle (ROV) dived to ocean depths between about 2,000 and 12,000ft and carried out 300 hours of filming.

It surveyed the giant mountain range that divides the Atlantic Ocean into east and west, to relay pictures of the never-seen-before species to the team on board the ship.

"One morning at 3am, sitting in the ROV cabin on board instructing the pilots where to go and looking at the pictures, we discovered three new species in the space of half an hour," said Prof Priede. "It was like Darwin landing in Patagonia."

In the north-west plains they found deep-sea enteropneust acorn worms. Previously only a few specimens of these worms had been known to science, in the Pacific Ocean.

Three types of the worm were discovered - one pink, one purple and one white - and each with a different shape.

Prof Priede said the worms were members of a little-known group of animals close to the missing link in evolution between backboned and invertebrate animals.

They have no eyes, sense organs or brain but there is a head and tail end, and the primitive "body plan" of backboned animals, he said.

In the past, biologists working in the deep ocean have seen only the spiral trace of sediment produced by the creature, and not the creature itself.

However, the team successfully filmed the primitive worms eating grit and sand in the bottom sediment of the ocean and leaving the characteristic spiral traces on the sea floor.