Thursday, May 19, 2011

Sea Lilies

The sea lilies and their relatives the feather stars are echinoderms (spiny-skinned animals) that have survived for 500 million years with hardly any changes. They give us a glimpse of what life was like in the ancient Cambrian seas.

Sea LiliesSea lilies and feather stars belong to the same family of spiny-skinned animals as starfish, sea urchins, and sea cucumbers. The body of an adult sea lily is attached to the deep ocean floor by a stalk. Feather stars usually live in shallower water. They are only attached to the ocean floor when they are growing; when they become
adults they can move around. The cuplike bodies of sea lilies and feather stars are supported by jointed, limblike structures called cirri. These grip the substrate when needed. The arms are arranged around the mouth at the top of the body cup.

Sea Lilies
Limited Movements
Sea LiliesSea lilies can bend and flex their stalks and arms. They move their body on the stalk in order to get the best flow of water through the branched arms. Feather stars are also able to swim about by flexing their arms in a beautiful, rhythmic swimming motion. 


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