The phylum Echinodermata is made up of spiny skinned sea creatures. These include sea lillies (crinoids), starfish, sea cucumbers and sea urchins. Animals in this phylum have radial symmetry. All Echinoderms are marine animals.
Echinoderms have a skeleton made up of a calcium material. These materials may form plates or spines. The calcium materials have a sponge-like structure which makes the plates strong, but light in weight.
They possess a body cavity that contains a water vascular system. This interal system of vessels are involved in respiration, eating, sensing the environment and movement. Many have a simple gut that passes food from mouth to the anus.
Many echinoderms also have the ability to regenerate. They may regenerate lost arms or even internal organs. Reproduction may be sexual or asexual.
The phylum of Echinodermata can be broken down into three main sub-phyla. These would be the starfish, sea urchin and crinoid types of echinoderms.
Most echinoderms are benthic creatures. They live primarily on the sea floor. Members of this phylum can be found in marine environments all over the globe. They may live in shallow coastal waters or be found at the bottom of deep-sea ocean trenches.
Humans and Echinoderms
Sea cucumbers and sea urchins are part of the diet in Southeast Asia. They are considered delicacies in that part of the world. In other countries, they are not part of the diet at all.
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Starfish, Sea Urchins and Allies, Earthlife.net.