Scientists have discovered a new gigantic colony of "brittle-stars" on the peak of a submerged mountain. The colony was discovered on the Macquarie Ridge, south of New Zealand.
Brittle Stars (Ophiuroidea), are closely related to starfish.
The main difference is that they do not, like sea stars, depend on tube feet. Brittle stars move fairly rapidly by wriggling their arms which are highly flexible and enable the animals to make either snake-like or rowing movements. Using their five flexible arms (which may reach up to 60 centimeters in length on the largest specimens) they can crawl across the sea-floor much faster and efficiently than the star fishes.
In the newly discovered colony the Brittlestars are tens of millions, living crammed together, arm tip to arm tip, packed so tightly that scientists have dubbed the seamount "brittlestar city".
Their incredible success is due to the seamount's shape and to the swirling circumpolar current flowing over and around it at roughly four kilometers per hour.
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 scientists recorded life at the Macquarie Ridge for the CenSeam programme, which is funded by the Census of Marine Life. Click here for more info
Photo and Video courtesy of Niwa