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Antedon
''Antedon'' is a genus of sessile, stemless crinoids found in shallow tropical and temperate marine environments worldwide. The genus first appears in the fossil record during the Cretaceous period. Characteristics Members of this genus have no stems but have five pairs of feathery arms arising from a central concave disc. There are a number of cirri or unbranched appendages on a low, cone-shaped dorsal ossicle, a bone-like structure in the centre of the disc. The mouth and the ambulacral grooves are also on the upper surface. Clawed cirri on the lower surface provide temporary attachment to the substrate. There is great variability in the morphological features in antedonids found in different habitats and the main distinguishing feature among the species is the number of cirri. Feeding ''Antedon'' is a filter feeder, feeding on small particules within the water colunm. Their feeding rhythms were observed and the tend to feed almost continuously. ''Antedon'' does not feed w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antedon Mediterranea
''Antedon mediterranea'' is a species of stalkless crinoid in the family Antedonidae, commonly known as the Mediterranean feather star. It is found on the seabed at moderate depths in the Mediterranean Sea. It is a filter feeder and captures plankton with its long feathery arms. Description ''Antedon mediterranea'' has a vestigial stalk, the base of which bears up to forty grasping cirri, articulated prehensile structures with which it can cling to a hard surface. Above this is the calyx, a small, cup-shaped structure, which is surrounded by five pairs of arms which bear feathery pinnules. The arms can be rolled up if danger threatens, but when they are extended to feed, they are about long. They are fragile but if one gets broken off, the animal can regenerate it. The colour of this crinoid is quite variable and ranges from white, yellow, orange or red to brown and dark purple, sometimes with bands of contrasting colour. Distribution and habitat ''Antedon mediterranea'' is fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
