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Vinctiplicata
The Vinctiplicata is a clade of Scalidophora uniting the Loricifera and the Priapulida, and representing the sister group to the Kinorhyncha. Its monophyly is supported on morphological grounds, although some molecular studies indicate that the Loricifera may be more closely related to the Nematomorpha Nematomorpha (sometimes called Gordiacea, and commonly known as horsehair worms, hairsnakes, or Gordian worms) are a phylum of parasitoid animals superficially similar to nematode worms in morphology, hence the name. Most species range in size f .... References Scalidophora Ecdysozoa unranked clades {{Protostome-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loricifera
Loricifera (from Latin, ''wikt:lorica, lorica'', corselet (armour) + ''ferre'', to bear) is a phylum of very small to microscopic marine cycloneuralian sediment-dwelling animals with 43 described species and approximately 100 more that have been collected and not yet described. Their sizes range from 100 μm to . They are characterised by a protective outer case called a Lorica (biology), lorica and their habitat is in the spaces between marine gravel to which they attach themselves. The phylum was discovered in 1983 by Reinhardt Kristensen, R.M. Kristensen, near Roscoff, France. They are among the most recently discovered groups of animals. They attach themselves quite firmly to the substrate, and hence remained undiscovered for so long. The first specimen was collected in the 1970s, and described in 1983. They are found at all depths, in different sediment types, and in all latitudes. Morphology The animals have a head, mouth, and digestive system, as well as the lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalidophora
Scalidophora is a group of marine pseudocoelomate ecdysozoans that was proposed on morphological grounds to unite three phyla: the Kinorhyncha, the Priapulida and the Loricifera. The three phyla have four characters in common — chitinous cuticle that is moulted, rings of scalids on the introvert, flosculi, and two rings of introvert retracts.Heiner, I., Kristensen, R.H. 2005. Two new species of the genus ''Pliciloricus'' (Loricifera, Pliciloricidae) from the Faroe Bank, North Atlantic. Zoologischer Anzeiger. 243: 121–138. The introvert and abdomen are separated by a distinct neck region in all groups, but in adult macroscopic priapulids it becomes rudimentary in ''Priapulus'' and is completely absent in ''Halicryptus''. However, the monophyly of the Scalidophora was not supported by two molecular studies, where the position of the Loricifera was uncertain or as sister to the Panarthropoda. Both studies supported a reduced Scalidophora comprising the Kinorhyncha and Priapulid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priapulid
Priapulida (priapulid worms, from Gr. πριάπος, ''priāpos'' 'Priapus' + Lat. ''-ul-'', diminutive), sometimes referred to as penis worms, is a phylum of unsegmented marine worms. The name of the phylum relates to the Greek god of fertility, because their general shape and their extensible spiny introvert (eversible) proboscis may resemble the shape of a human penis. They live in the mud, except for a few tropical meiobenthic species which live in medium- to coarse-grained sands, and are found in comparatively shallow waters to deep waters and no warmer than 12–13°C. Some species show a remarkable tolerance for hydrogen sulfide, anoxia and low salinity. ''Halicryptus spinulosus'' appears to prefer brackish shallow waters. They can be quite abundant in some areas. In an Alaskan bay as many as 85 adult individuals of '' Priapulus caudatus'' per square meter has been recorded, while the density of its larvae can be as high as 58,000 per square meter (5,390 per square foot). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinorhyncha
Kinorhyncha (, ' "snout") is a phylum of small marine invertebrates that are widespread in mud or sand at all depths as part of the meiobenthos. They are commonly called mud dragons. Modern species are or less, but Cambrian forms could reach . Anatomy Kinorhynchs are limbless animals, with a body consisting of a head, neck, and a trunk of eleven segments. They are the only members of Ecdysozoa, except from the panarthropoda, with a segmented body. Juveniles have eight or nine segments, depending on genus, with the last two or three being added later during growth. A Cambrian species, Eokinorhynchus rarus, had about twice as many segments as present forms. Like other ecdysozoans they do not have external cilia, but instead have a number of spines along the body, plus up to seven circles of spines around the head. These spines are used for locomotion, withdrawing the head and pushing forward, then gripping the substrate with the spines while drawing up the body. The body ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematomorpha
Nematomorpha (sometimes called Gordiacea, and commonly known as horsehair worms, hairsnakes, or Gordian worms) are a phylum of parasitoid animals superficially similar to nematode worms in morphology, hence the name. Most species range in size from , reaching in extreme cases, and in diameter. Horsehair worms can be discovered in damp areas, such as watering troughs, swimming pools, streams, puddles, and cisterns. The adult worms are free-living, but the larvae are parasitic on arthropods, such as beetles, cockroaches, mantises, orthopterans, and crustaceans. About 351 freshwater species are known and a conservative estimate suggests that there may be about 2000 freshwater species worldwide. The name "Gordian" stems from the legendary Gordian knot. This relates to the fact that nematomorphs often coil themselves in tight balls that resemble knots. Description and biology Nematomorphs possess an external cuticle without cilia. Internally, they have only longitudinal muscle and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
