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Cephalodiscus Planitectus
''Cephalodiscus planitectus'' is a sessile hemichordate belonging to the order Cephalodiscida. Distribution It is found at a depth of 100–300 metres off the island of Jōgashima, Sagami Bay, Japan. Anatomy There are three pairs of arms with tentacles. Phylogenetics ''Cephalodiscus planitectus'' is the most divergent of all ''Cephalodiscus'' species, with Miyamoto, Nishikawa and Namikawa (2020) suggesting that it constitutes a sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ... to all existing ''Cephalodiscus'' species. References planitectus Animals described in 2020 {{hemichordate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animalia
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have 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 bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterobranchia
Pterobranchia is a class of small worm-shaped animals. They belong to the Hemichordata, and live in secreted tubes on the ocean floor. Pterobranchia feed by filtering plankton out of the water with the help of cilia attached to tentacles. There are about 25 known living pterobranch species in three genera, which are ''Rhabdopleura'', '' Cephalodiscus'', and '' Atubaria''. On the other hand, there are several hundred extinct genera, some of which date from the Cambrian Period. The class Pterobranchia was established by Ray Lankester in 1877. It contained, at that time, the single genus ''Rhabdopleura''. ''Rhabdopleura'' was at first regarded as an aberrant polyzoon, but when the ''Challenger'' report on '' Cephalodiscus'' was published in 1887, it became clear that ''Cephalodiscus'', the second genus now included in the order, had affinities with the Enteropneusta. Electron microscope studies have suggested that pterobranchs belong to the same clade as the extinct grapto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalodiscida
Cephalodiscida is one of two orders in the class Pterobranchia, which are small, worm-shaped animals. Members belong to the hemichordates. Species in this order are sessile, living in clear water and secrete tubes on the ocean floor. Taxonomy The order is a small one, with only two known families, each containing a single genus. The validity of the family Atubaridae, who has only a sole member, is regarded as questionable. * Order Cephalodiscida Fowler 1892 ** Family Cephalodiscidae Harmer 1905 *** Genus †'' Aellograptus'' Obut 1964 *** Genus †'' Eocephalodiscus'' Kozlowski 1938 ex Kozlowski 1949 *** Genus †'' Melanostrophus'' Öpik 1930 ex Öpik 1933 *** Genus †'' Pterobranchites'' Kozlowski 1967 *** Genus '' Atubaria'' Sato 1936 *** Genus ''Cephalodiscus ''Cephalodiscus'' is a genus of hemichordates in the monotypic family Cephalodiscidae of the order Cephalodiscida. Description Unlike ''Rhabdopleura'', ''Cephalodiscus'' species do not form large colonies and are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalodiscus
''Cephalodiscus'' is a genus of hemichordates in the monotypic family Cephalodiscidae of the order Cephalodiscida. Description Unlike ''Rhabdopleura'', ''Cephalodiscus'' species do not form large colonies and are only pseudocolonial. ''Cephalodiscus'' zooids are also more mobile than their ''Rhabdopleura'' counterparts, and are able to move around within tubarium, tubaria. ''Cephalodiscus'' zooids can be produced via asexual budding. There are a few pairs of tentacled arms, whereas ''Rhabdopleura'' has only one pair of arms. Species 19 living species of ''Cephalodiscus'' have been described: * ''Cephalodiscus agglutinans'' Harmer & Ridewood, 1914 * ''Cephalodiscus atlanticus'' Bayer, 1962 * ''Cephalodiscus australiensis'' Johnston & Muirhead, 1951 * ''Cephalodiscus calciformis'' Emig, 1977 * ''Cephalodiscus densus'' Andersson 1907 [''Cephalodiscus rarus'' Andersson, 1907; ''Cephalodiscus anderssoni'' Gravier 1912] * ''Cephalodiscus dodecalophus'' McIntosh 1882 * ''Cephalodisc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sessility (zoology)
Sessility is the biological property of an organism describing its lack of a means of self-locomotion. Sessile organisms for which natural ''motility'' is absent are normally immobile. This is distinct from the botanical concept of sessility, which refers to an organism or biological structure attached directly by its base without a stalk. Sessile organisms can move via external forces (such as water currents), but are usually permanently attached to something. Organisms such as corals lay down their own substrate from which they grow. Other sessile organisms grow from a solid such as a rock, dead tree trunk, or a man-made object such as a buoy or ship's hull. Mobility Sessile animals typically have a motile phase in their development. Sponges have a motile larval stage and become sessile at maturity. Conversely, many jellyfish develop as sessile polyps early in their life cycle. In the case of the cochineal, it is in the nymph stage (also called the crawler stage) that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemichordate
Hemichordata is a phylum which consists of triploblastic, enterocoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. They appear in the Lower or Middle Cambrian and include two main classes: Enteropneusta (acorn worms), and Pterobranchia. A third class, Planctosphaeroidea, is known only from the larva of a single species, ''Planctosphaera pelagica''. The class Graptolithina, formerly considered extinct, is now placed within the pterobranchs, represented by a single living genus ''Rhabdopleura''. Acorn worms are solitary worm-shaped organisms. They generally live in burrows (the earliest secreted tubes) and are deposit feeders, but some species are pharyngeal filter feeders, while the family Torquaratoridae are free living detritivores. Many are well known for their production and accumulation of various halogenated phenols and pyrroles. Pterobranchs are filter-feeders, mostly colonial, living in a collageno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jōgashima
is an island in the municipality of Miura, Kanagawa Prefecture, Japan, off the southernmost and western tip of Miura Peninsula, facing Sagami Bay. It is home to the Jōgashima Lighthouse, the fourth oldest western style lighthouse to be built in Japan. Jōgashima Park is located on the eastern part of the island. Jōgashima is connected to the mainland by a box-girder bridge since 1959, which was the longest in Asia in 1963."Recently Jogashima and Miura have been linked by the longest box-girder bridge in the Orient. The total length of the bridge is 575 meters; the central span is 90 meters long, the adjoining spans 70.3 meters and the remaining spans 40 meters" Japan's construction, 1963, Kaigai Kensetsu Kyōkai (Japan) File:Jougashima tree.JPG, Trees in Jōgashima. File:Jogashima ohashi bridge and Hakusyuuhi.jpg, The bridge. File:Jougashima Ooshima.JPG, Ōshima from Jōgashima. File:Jougashima South3.JPG, Mount Fuji , or Fugaku, located on the island of Honshū, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagami Bay
lies south of Kanagawa Prefecture in Honshu, central Japan, contained within the scope of the Miura Peninsula, in Kanagawa, to the east, the Izu Peninsula, in Shizuoka Prefecture, to the west, and the Shōnan coastline to the north, while the island of Izu Ōshima marks the southern extent of the bay. It lies approximately southwest of the capital, Tokyo. Cities on the bay include Odawara, Chigasaki, Fujisawa, Hiratsuka, Itō, and Kamakura. History The center of the Great Kantō earthquake in 1923 was deep beneath Izu Ōshima Island in Sagami Bay. It devastated Tokyo, the port city of Yokohama, and the surrounding prefectures of Chiba, Kanagawa, and Shizuoka, and caused widespread damage throughout the Kantō region. The shallow nature of the seabed on the north of the bay, and the funnelling effect of tsunami and typhoon wave energy, contributed to certain parts of the Shonan coast having suffered considerable damage, including the destruction of the Kōtoku-in temple hou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Group
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same taxonomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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