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Velella Velella On The Beach
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Distribution and habitat
Velella velella occurs in warm and temperate waters in all the world's oceans. They live at the water/air interface, with the float above the water, and polyps hanging down about a centimetre below. Organisms that live partly in and partly out of the water like this are known as pleuston. Offshore boaters sometimes encounter thousands of V. velella on the water surface.
The small rigid sail projects into the air and catches the wind . However Velella sails always align along the direction of the wind where the sail may act as an aerofoil so that the animals tend to sail downwind at a small angle to the wind.
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