12 Bizarre Sea Creatures

These Chaenocephalus aceratus fish are highly adapted to life the cold waters of Antarctica's continental shelf. Their blood is filled with anti-freeze, but no red blood cells. This is among the many creatures recently photographed by the British Antarctic Survey in the Southern Ocean, one of the fastest-warming seas in the world.

Also called a sea cucumber or Holothuroid, this truly deserves the name sea pig. This was one of the most common and abundant animals caught off the coast of Antarctica by the international research team aboard the BAS Royal Research Ship James Clark Ross. Sea cucumbers are important in processing the sediment (like earthworms on land) but their numbers worldwide have been threatened by recent fisheries. "Few people realize just how rich in biodiversity the Southern Ocean is – even a single trawl can reveal a fascinating array of weird and wonderful creatures as would be seen on a coral reef. These animals are potentially very good indicators of environmental change as many occur in the shallows, which are changing fast, but also in deeper water which will warm much less quickly," said research cruise leader Dr. David Barnes of British Antarctic Survey.

In the absence of crabs and the presence of oxygen-rich waters amphipods like this sandhopper grow to unusually large proportions. Krill is the largest source of food for penguins, seals and whales. "Changes at the Earth’s surface directly affect the surrounding ocean and the marine animals living there. For example accelerating glacier melt, collapse of ice shelves and shrinking winter sea-ice all seem to be impacting sea life," said British Antarctic Survey biologist Dr. Sophie Fielding, a krill expert. "We want to understand that impact and what the implications for the food chain may be."

Polychaete worms like this are often the most abundant large organisms, particularly on Antarctica's cold continental shelf.

This group of animals share commonalities with woodlice on land. They are abundant in Antarctica's deep water. Antarcturus tend to hang off seaweed, sponges or (as here) sea fans to catch tiny plankton in the water.

This octopus, probabl a Pareledone, seems to be particularly common. "Our new studies on the diverse range of marine creatures living in the deep waters of the Bellingshausen Sea will help us build a more complete picture of Antarctica's marine biodiversity and give us an important baseline against which we can compare future impact on marine life," Barnes said.

These woodlice of the sea resemble fossil trilobites; they appear almost as though they have been squashed. Here, the translucent creatures are seen from above (left) and below (right).

Feather stars are very mobile as both adults and larvae, eat phytoplankton and as such may track the changes caused by global warming. Aea ice retreat and marine algae distribution are two of the strongest impacts of climate change measured in the region to date. "We can now begin to get a better understanding of how the ecosystem will adapt to change," Barnes said. "Our research on species living in the waters surrounding the BAS Rothera Research Station on the Antarctic Peninsula shows that some species are incredibly sensitive to temperature changes."

This beautiful brittle star, Gorganocephalus, was filmed expanding its curly, branching arms out over about a minute. It was found with its arms intertwined with an octocoral. Posed here, it is able to filter feed on food floating by in the water above the seabed.

Jellies like this can be very abundant in Southern Ocean surface waters and it is widely suggested that they will be amongst the big winners in the more acidic, warmer ocean that results from high levels of carbon dioxide in the atmosphere.

Skates are rare in Antarctica. They live just above the seabed and have crushing mouthparts to eat shellfish and other animals living on the seabed. Most crushing predators became extinct in Antarctica when it cooled, but as it warms species such as this skate may become more common and have a big impact on the wide variety of native seabed life that have lived with few predators for millions of years. "Although many of these animals are tiny, their behavior helps us paint a much bigger picture in terms of how marine life may react to changes to the environment," said Stefanie Kaiser, a German specialist on small seabed animals.

This soft coral, the first the research team encountered in its expedition, has yet to be identified.