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Davidaster
''Davidaster'' is a genus of crinoid Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are ...s. According to the World Register of Marine Species, a number of species that originally were included in the genus '' Nemaster'' are now included in ''Davidaster''. Members of this genus have wedge-shaped arms, except for the basal ones, often longer than they are wide. The mouth is off centre and there are no pinnule combs after pinnule 3. The primary comb has the teeth widely separated and confluent with the lateral edge of the segment. Species *Species '' Davidaster discoideus'' (Carpenter, 1888) :synonyms ''Nemaster discoidea'' (Carpenter, 1888) ::::''Nemaster insolitus'' AH Clark, 1917 *Species '' Davidaster rubiginosus'' (Pourtalès, 1869) :synonyms ''Nemaster iowensis'' Springer, 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Davidaster Discoideus
''Davidaster discoideus'' or the beaded crinoid is a species of feather star in the family Comatulidae. It was previously known as ''Nemaster discoidea'' but the World Register of Marine Species has determined that the valid name is ''Davidaster discoideus''. It is found on reefs in the Caribbean Sea and northern coast of South America. Description The beaded crinoid has a cup shaped body, usually hidden from sight, from which about twenty arms project. Only a few of these are usually visible at one time and each can be curled up in a coil. Short pinnules extend from either side of the arms like vanes on a feather. Both the arms and the pinnules are formed from a large number of jointed plates which gives them great overall flexibility. There is an ambulacral groove along the oral surface of each pinnule which is continuous with grooves on the arms. These are linked to grooves leading to the mouth forming feeding channels. The grooves have flap-like lappets overhanging them. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Davidaster Rubiginosus
''Davidaster rubiginosus'' or the orange sea lily is a species of crinoid in the family Comatulidae. At one time it was classified as ''Nemaster rubiginosa'' but the World Register of Marine Species has determined that the valid name is ''Davidaster rubiginosus''. It is found on reefs in the tropical western Atlantic and the Caribbean Sea. Description The orange sea lily is a stalkless crinoid. It has twenty to thirty five arms long radiating from the calyx, a cup-like body with a lid, the tegmen. Each arm is feather-like and has many pinnules projecting alternately from one side and the other. These have an ambulacral groove on the oral surface which is continuous with the groove on the arm. The arms are usually orange with yellow curved up tips but there is some variation in colour and they are sometimes white with black tips. The grooves are black. The arms and pinnules are composed of a series of jointed plates and there are three tube feet at each junction. The tube fee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comatulidae
Comatulidae is a family of comatulid crinoids. Since 2015, it replaces the family Comasteridae. Description and characteristics This family is of recent restoration, and still has no consensual description. However the description of the family Comasteridae remains partially valid. This family counts between 93 and 95 species, distributed in 21 genera, which makes it the second most diversified family of crinoids the behind Antedonidae, representing approximately 1/6th of known crinoid species. It contains most of the big species of shallow tropical feather stars, in particular in the Indo-Pacific. List of genera This family has been recently restored following genetic works from Charles Messing's team. It contains the following genera: * sub-family Comatellinae Summers, Messing, Rouse, 2014 ** genus '' Alloeocomatella'' Messing, 1995 -- 2 species ** genus '' Comatella'' AH Clark, 1908 -- 2 species ** genus '' Davidaster'' Hoggett & Rowe, 1986 -- 2 species ** genus '' N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinodermata
An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies". Adult echinoderms are found on the sea bed at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7,000 living species, making it the second-largest grouping of deuterostomes, after the chordates. Echinoderms are the largest entirely marine phylum. The first definitive echinoderms appeared near the start of the Cambrian. The echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the biotic desert of the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs, and limbs; in some cases, they can undergo complete regeneration from a single limb. Geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crinoidea
Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are members of the largest crinoid order, Comatulida. Crinoids are echinoderms in the phylum Echinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. They live in both shallow water and in depths as great as . Adult crinoids are characterised by having the mouth located on the upper surface. This is surrounded by feeding arms, and is linked to a U-shaped gut, with the anus being located on the oral disc near the mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognised, in most crinoids the five arms are subdivided into ten or more. These have feathery pinnules and are spread wide to gather planktonic particles from the water. At some stage in their lives, most crinoids have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Articulata (Crinoidea)
Articulata are a subclass or superorder within the class Crinoidea, including the only living crinoid species. They are commonly known as sea lilies (stalked crinoids) or feather stars (unstalked crinoids). The Articulata are differentiated from the extinct subclasses by their lack of an anal plate in the adult stage and the presence of an entoneural system. Articulata first appeared in the fossil record during the Triassic period although other, now extinct crinoid groups, originated in the Ordovician. Characteristics Articulata exhibit pentamerous symmetry. The stalk, which consists of numerous disks held together by ligaments, supports a calyx or cup made of circlets of calcerous plates. In Comatulids, the stalk develops following the larval stage, but the juveniles shed all but the topmost disk to take up a free-living existence. Five often branched arms, which consist of articulated series of ossicles, extend from the oral plate and form the food-capture mechanism of Articula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comatulida
Comatulida is an order of crinoids. Members of this order are known as feather stars and mostly do not have a stalk as adults. The oral surface with the mouth is facing upwards and is surrounded by five, often divided rays with feathery pinnules. Comatulids live on the seabed and on reefs in tropical and temperate waters. Taxonomy Bourgueticrinida, the sea lilies, has traditionally been viewed as an order of Articulata and a sister taxon to Comatulida. A study published in 2011 suggested that it should be renamed Bourgueticrinina and viewed as a suborder of Comatulida. Characteristics Like other echinoderms, comatulids have pentamerous symmetry (five sided) as adults though the larvae have bilateral symmetry. Late in their development, the larvae are attached to the seabed by a stalk, but this is broken at metamorphosis and the juvenile crinoid is free living. The body has an endoskeleton made from a number of articulated calcareous plates known as ossicles covered by a thin e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crinoid
Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are members of the largest crinoid order, Comatulida. Crinoids are echinoderms in the phylum Echinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. They live in both shallow water and in depths as great as . Adult crinoids are characterised by having the mouth located on the upper surface. This is surrounded by feeding arms, and is linked to a U-shaped gut, with the anus being located on the oral disc near the mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognised, in most crinoids the five arms are subdivided into ten or more. These have feathery pinnules and are spread wide to gather planktonic particles from the water. At some stage in their lives, most crinoids have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nemaster
''Nemaster'' is a monotypic genus of echinoderms belonging to the family Comatulida Comatulida is an order of crinoids. Members of this order are known as feather stars and mostly do not have a stalk as adults. The oral surface with the mouth is facing upwards and is surrounded by five, often divided rays with feathery pinnules .... The only species is ''Nemaster grandis''. The species is found in Central America and Australia. References Comatulidae Crinoid genera Monotypic echinoderm genera {{crinoidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
