Brittle-star 'city' discovered on underwater mountain

Earth 19 May 2008
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(Image: NIWA)

Scientists have captured the first images of a novel brittle-star “city” that has colonized the peak of a submerged mountain. The colony was discovered on the Macquarie Ridge, an underwater mountain range south of New Zealand.

It is mostly made up of brittle stars (Ophiuroidea), which are closely related to starfish. Tens of millions of the creatures were found living crammed together.

Watch a slideshow of the brittle star colony


They are able to survive because of a swirling circumpolar current flowing over and around the seamount. It allows the brittle stars to capture passing food simply by raising their arms, and also sweeps away would-be predators such as fish.

The city was discovered during an expedition by the Census of Marine Life to survey the Macquarie Ridge aboard the research vessel Tangaroa.


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