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Palaeonemertea
Palaeonemertea is a class of primitive nemertean worm. It may be para- or polyphyletic, consisting of three to five clades and totalling about 100 species. These worms have several apparently simple features and, as their name suggests, they are often considered to be the most primitive nemerteans. The primary body-wall musculature consists of an outer circular layer overlying a longitudinal layer. The group includes genera such as '' Cephalothrix'' in which the nerve cords are inside the body-wall longitudinal muscle, and ''Tubulanus ''Tubulanus'' is a genus of primitive nemertean worms in the order Palaeonemertea. Species The World Register of Marine Species includes the following species in the genus: * '' Tubulanus albocinctus'' (Coe, 1904) * '' Tubulanus annulatus'' (Mo ...'', in which the nerve cords are between the outer circular muscle and the epidermis. Tubulanids are commonly encountered in rocky areas of intertidal zones in the northern hemisphere. They are often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nemertea
Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many have patterns of yellow, orange, red and green coloration. The foregut, stomach and intestine run a little below the midline of the body, the anus is at the tip of the tail, and the mouth is under the front. A little above the gut is the rhynchocoel, a cavity which mostly runs above the midline and ends a little short of the rear of the body. All species have a proboscis which lies in the rhynchocoel when inactive but everts to emerge just above the mouth to capture the animal's prey with venom. A highly extensible muscle in the back of the rhynchocoel pulls the proboscis in when an attack ends. A few species with stubby bodies filter feed and have suckers at the front and back ends, with which they attach to a host. The brain is a rin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nemertean
Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many have patterns of yellow, orange, red and green coloration. The foregut, stomach and intestine run a little below the midline of the body, the anus is at the tip of the tail, and the mouth is under the front. A little above the gut is the rhynchocoel, a cavity which mostly runs above the midline and ends a little short of the rear of the body. All species have a proboscis which lies in the rhynchocoel when inactive but everts to emerge just above the mouth to capture the animal's prey with venom. A highly extensible muscle in the back of the rhynchocoel pulls the proboscis in when an attack ends. A few species with stubby bodies filter feed and have suckers at the front and back ends, with which they attach to a host. The brain is a ring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeonemertea
Palaeonemertea is a class of primitive nemertean worm. It may be para- or polyphyletic, consisting of three to five clades and totalling about 100 species. These worms have several apparently simple features and, as their name suggests, they are often considered to be the most primitive nemerteans. The primary body-wall musculature consists of an outer circular layer overlying a longitudinal layer. The group includes genera such as '' Cephalothrix'' in which the nerve cords are inside the body-wall longitudinal muscle, and ''Tubulanus ''Tubulanus'' is a genus of primitive nemertean worms in the order Palaeonemertea. Species The World Register of Marine Species includes the following species in the genus: * '' Tubulanus albocinctus'' (Coe, 1904) * '' Tubulanus annulatus'' (Mo ...'', in which the nerve cords are between the outer circular muscle and the epidermis. Tubulanids are commonly encountered in rocky areas of intertidal zones in the northern hemisphere. They are often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalotrichidae
Cephalothricidae is a family of worms belonging to the order Palaeonemertea. Genera: * '' Astemma'' Örsted, 1843 * '' Balionemertes'' Sundberg, Gibson & Olsson, 2003 * '' Cephalothrix'' Örsted, 1843 References Palaeonemertea Nemertea families {{nemertean-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubulanidae
Tubulanidae is a family of primitive nemertean worms in the order Palaeonemertea. Characteristics Worms in this family have slightly flattened, rounded heads and approximately cylindrical bodies. Apart from the genera, '' Callinera'' and '' Carinina'', worms in this family have paired cerebral sensory organs located on either side of the constriction where the head joins the body. Some species are red or brown, often with distinctive white bands or longitudinal stripes, but others are small and so translucent that their cerebral organs can be seen through the skin. Genera The World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ... includes the following genera in the group: * '' Callinera'' Bergendal, 1900 * '' Carinesta'' Punnett, 1900 * '' Carinina' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carinomidae
Carinomidae is a family of worms belonging to the order Palaeonemertea. Genera: * '' Carinoma'' Oudemans, 1885 * '' Carinomella'' Coe, 1905 * '' Statolitonemertes'' Korotkevich, 1982 References Palaeonemertea Nemertea families {{nemertean-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubulanus
''Tubulanus'' is a genus of primitive nemertean worms in the order Palaeonemertea. Species The World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ... includes the following species in the genus: * '' Tubulanus albocinctus'' (Coe, 1904) * '' Tubulanus annulatus'' (Montagu, 1804) * '' Tubulanus aureus'' (Joubin, 1904) * '' Tubulanus borealis'' Friedrich, 1936 * '' Tubulanus capistratus'' (Coe, 1901) * '' Tubulanus cingulatus'' (Coe, 1904) * '' Tubulanus ezoensis'' Yamaoka, 1940 * '' Tubulanus floridanus'' Coe, 1951 * '' Tubulanus frenatus'' (Coe, 1904) * '' Tubulanus groenlandicus'' (Bergendal, 1902) * '' Tubulanus holorhynchocoelomicus'' Friedrich, 1958 * '' Tubulanus hylbomi'' Gibson & Sundberg, 1999 * '' Tubulanus linearis'' (McIntosh, 1874) * '' Tubul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalothrix
''Cephalothrix'' is a genus of nemerteans belonging to the family Cephalothricidae. The genus has cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext .... Species Species: *'' Cephalothrix adriatica'' *'' Cephalothrix alba'' *'' Cephalothrix aliena'' References Palaeonemertea Nemertea genera {{nemertean-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubulaniformes
''Tubulaniformes'' is an order of worms belonging to the class Palaeonemertea. Families: * Callineridae Bergendal, 1901 * Carinomellidae Chernyshev, 1995 * Tubulanidae Bürger, 1905 References {{Taxonbar, from=Q109442195 Nemerteans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventral Nerve Cord
The ventral nerve cord is a major structure of the invertebrate central nervous system. It is the functional equivalent of the vertebrate spinal cord. The ventral nerve cord coordinates neural signaling from the brain to the body and vice versa, integrating sensory input and locomotor output. Decapitated insects can still walk, groom, and mate, illustrating that the circuitry of the ventral nerve cord is sufficient to perform complex motor programs without brain input. Structure The ventral nerve cord runs down the Anatomical terms of location, ventral ("belly", as opposed to back) plane of the organism. It contains ascending and Descending neuron, descending neurons that relay information to and from the brain, Motor neuron, motor neurons that project into the body and synapse onto muscles, Sensory neuron, sensory neurons that receive information from the body and environment, and Interneuron, interneurons that coordinate circuitry of all of these neurons. Ventral nerve cord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambrosius Hubrecht
Ambrosius Arnold Willem Hubrecht (2 March 1853, in Rotterdam – 21 March 1915, in Utrecht) was a Dutch zoologist. Hubrecht studied zoology at Utrecht University with Harting and Donders, for periods joining Selenka in Leiden and later Erlangen, and Gegenbauer in Heidelberg. He graduated ''magna cum laude'' with Harting in 1874 with a study on nemertine worms. In 1875–1882 he worked at the ''Rijksmuseum van Natuurlijke Historie'' in Leiden, where he was the curator of ichthyology and herpetology, and in 1882 became professor at Utrecht. In 1890–1891 he traveled in Java, Sumatra, and Borneo, where he made embryological studies, notably on the tarsier. He visited the United States in 1896 and 1907. Honorary degrees were conferred on him by Princeton University, the University of St Andrews, the University of Dublin, the University of Glasgow ( LL.D 1901), and the University of Giessen. Hubrecht´s most important work was in embryology and placentation of the mammals. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
