page_title: Semibalanus balanoides
section_title: Feeding
hierarchical_section_title: Semibalanus balanoides / Life cycle / Feeding
caption_attribution_description: Dansk: Rur (Semibalanus balanoides) ved store sten i vandkanten omkring havnemolen i Upernavik, Grønland. Billedet er taget gennem vandspejlet - derfor det lette forvrængning. Diameteren for hvert individ er omkring 10 mm. Seks fjeragtige lemmer stikker ud fra hvert dyr. De kæmmer rytmisk gennem vandet for at opsamle føde. English: Barnacles (Semibalanus balanoides) at the waterline on some large rocks at the mole in Upernavik harbour, Greenland. The image is taken by placing the lens of the camera as close as possible to the water surface, thus the wavy distortions. Each individual has a diameter of approximately 10 mm. When submerged in water, the animal extends six limbs in the water and moves them rhythmically combing the water for food.
context_page_description: Semibalanus balanoides is a common and widespread boreo-arctic species of acorn barnacle. It is common on rocks and other substrates in the intertidal zone of north-western Europe and both coasts of North America.
context_section_description: Semibalanus balanoides is a filter feeder, using its thoracic appendages, or cirri, to capture zooplankton and detritus from the water. If there is a current, then the barnacle holds its cirri stiffly into the flow, but when there is no current, the barnacle beats its cirri rhythmically. Plankton levels are highest in Spring and Autumn, and drop significantly during Winter, when the barnacles are dependent on reserves of food which they have stored.
caption: S. balanoides feeding, Upernavik, Greenland
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