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Beroids
Beroidae is a family of ctenophores or comb jelly, comb jellies more commonly referred to as the beroids. It is the only family within the monotypic order Beroida and the class Nuda. They are distinguished from other comb jellies by the complete absence of tentacles, in both juvenile and adult stages. Species of the family Beroidae are found in all the world's oceans and seas and are free-swimmers that form part of the plankton. Anatomy Some members of the diverse genus ''Beroe'' may occasionally attain a length of up to , though most species and individuals are less than about 10 cm; ''Neis cordigera'' is among the largest species in the class, often exceeding in length. The body is melon or cone-shaped with a wide mouth and pharynx and a capacious gastrovascular cavity. Many meridional canals branch off this and form a network of diverticulae in the mesogloea. There are no tentacles but there are a row of branched papillae, forming a figure of eight around the aboral tip. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenophore2
Ctenophora (; ctenophore ; ) comprise a phylum of marine invertebrates, commonly known as comb jellies, that inhabit sea waters worldwide. They are notable for the groups of cilia they use for swimming (commonly referred to as "combs"), and they are the largest animals to swim with the help of cilia. Depending on the species, adult ctenophores range from a few millimeters to in size. Only 100 to 150 species have been validated, and possibly another 25 have not been fully described and named. The textbook examples are cydippids with egg-shaped bodies and a pair of retractable tentacles fringed with tentilla ("little tentacles") that are covered with colloblasts, sticky cells that capture prey. Their bodies consist of a mass of jelly, with a layer two cells thick on the outside, and another lining the internal cavity. The phylum has a wide range of body forms, including the egg-shaped cydippids with retractable tentacles that capture prey, the flat generally combless platyct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenophores
Ctenophora (; ctenophore ; ) comprise a phylum of marine invertebrates, commonly known as comb jellies, that inhabit sea waters worldwide. They are notable for the groups of cilia they use for swimming (commonly referred to as "combs"), and they are the largest animals to swim with the help of cilia. Depending on the species, adult ctenophores range from a few millimeters to in size. Only 100 to 150 species have been validated, and possibly another 25 have not been fully described and named. The textbook examples are cydippids with egg-shaped bodies and a pair of retractable tentacles fringed with tentilla ("little tentacles") that are covered with colloblasts, sticky cells that capture prey. Their bodies consist of a mass of jelly, with a layer two cells thick on the outside, and another lining the internal cavity. The phylum has a wide range of body forms, including the egg-shaped cydippids with retractable tentacles that capture prey, the flat generally combless pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comb Jelly
Ctenophora (; ctenophore ; ) comprise a phylum of marine invertebrates, commonly known as comb jellies, that inhabit sea waters worldwide. They are notable for the groups of cilia they use for swimming (commonly referred to as "combs"), and they are the largest animals to swim with the help of cilia. Depending on the species, adult ctenophores range from a few millimeters to in size. Only 100 to 150 species have been validated, and possibly another 25 have not been fully described and named. The textbook examples are cydippids with egg-shaped bodies and a pair of retractable tentacles fringed with tentilla ("little tentacles") that are covered with colloblasts, sticky cells that capture prey. Their bodies consist of a mass of jelly, with a layer two cells thick on the outside, and another lining the internal cavity. The phylum has a wide range of body forms, including the egg-shaped cydippids with retractable tentacles that capture prey, the flat generally combless pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuda
Beroidae is a family of ctenophores or comb jellies more commonly referred to as the beroids. It is the only family within the monotypic order Beroida and the class Nuda. They are distinguished from other comb jellies by the complete absence of tentacles, in both juvenile and adult stages. Species of the family Beroidae are found in all the world's oceans and seas and are free-swimmers that form part of the plankton. Anatomy Some members of the diverse genus ''Beroe'' may occasionally attain a length of up to , though most species and individuals are less than about 10 cm; '' Neis cordigera'' is among the largest species in the class, often exceeding in length. The body is melon or cone-shaped with a wide mouth and pharynx and a capacious gastrovascular cavity. Many meridional canals branch off this and form a network of diverticulae in the mesogloea. There are no tentacles but there are a row of branched papillae, forming a figure of eight around the aboral tip. The sack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neis Cordigera
''Neis'' is a genus of nudan ctenophores. It is a monotypic genus containing the single species ''Neis cordigera''. It occurs only near Australia. As all beroids, it is a free-swimmer that form part of the plankton. ''Neis cordigera'' is among the largest species in the class, often exceeding in length. It is somewhat flattened and characterized by a pair of trailing gelatinous "wings" that extend beyond the aboral tip. Like other comb jellies, the body wall of nudans consists of an outer epidermis and an inner gastrodermis, separated by a jelly-like mesoglea Mesoglea refers to the extracellular matrix found in cnidarians like coral or jellyfish that functions as a hydrostatic skeleton. It is related to but distinct from mesohyl, which generally refers to extracellular material found in sponges. Desc .... The mesoglea has pigments that give many nudan species a slightly pink color; ''Neis cordigera'' may be yellowish or a deep orange-red. The aboral end is extended into two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neis
''Neis'' is a genus of nudan ctenophores. It is a monotypic genus containing the single species ''Neis cordigera''. It occurs only near Australia. As all beroids, it is a free-swimmer that form part of the plankton. ''Neis cordigera'' is among the largest species in the class, often exceeding in length. It is somewhat flattened and characterized by a pair of trailing gelatinous "wings" that extend beyond the aboral tip. Like other comb jellies, the body wall of nudans consists of an outer epidermis and an inner gastrodermis, separated by a jelly-like mesoglea Mesoglea refers to the extracellular matrix found in cnidarians like coral or jellyfish that functions as a hydrostatic skeleton. It is related to but distinct from mesohyl, which generally refers to extracellular material found in sponges. Desc .... The mesoglea has pigments that give many nudan species a slightly pink color; ''Neis cordigera'' may be yellowish or a deep orange-red. The aboral end is extended into two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Sea
The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine. The Black Sea is supplied by major rivers, principally the Danube, Dnieper, and Don. Consequently, while six countries have a coastline on the sea, its drainage basin includes parts of 24 countries in Europe. The Black Sea covers (not including the Sea of Azov), has a maximum depth of , and a volume of . Most of its coasts ascend rapidly. These rises are the Pontic Mountains to the south, bar the southwest-facing peninsulas, the Caucasus Mountains to the east, and the Crimean Mountains to the mid-north. In the west, the coast is generally small floodplains below foothills such as the Strandzha; Cape Emine, a dwindling of the east end of the Balkan Mountains; and the Dobruja Plateau considerably ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beroe Gracilis
''Beroe gracilis'' is a species of comb jelly in the family Beroidae. It is a free-swimming species found in the North Sea, the Atlantic Ocean and the Mediterranean Sea. Description ''Beroe gracilis'' is a translucent, elongated, hollow, cylindrical animal with a maximum length of about . Like the other members of the family Beroidae, it has no tentacles. The anterior end, with the gaping mouth at its tip, is slightly broader than the closed, posterior end. At the posterior end there is a statocyst, a flattened structure shaped like a figure-of-eight. From this, eight rows of combs with cilia radiate and extend three-quarters of the way along the body wall; it is the beating of these cilia that drive the animal forward, and their movement creates characteristic multicoloured sparkles. The general colour of the body wall is slightly milky, sometimes bluish or pinkish. The gut and its diverticula can be seen through the body wall. Distribution and habitat ''Beroe gracilis'' occurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Friedrich Von Eschscholtz
Johann Friedrich Gustav von Eschscholtz (1 November 1793 – 7 May 1831)Sterling (1997) was a Baltic German physician, naturalist, and entomologist. He was one of the earliest scientific explorers of the Pacific region, making significant collections of flora and fauna in Alaska, California, and Hawaii. Biography Eschscholtz was born in the Livonian city of Dorpat, then part of the Russian Empire. His parents, Johann Gottfried and Katherine Hedwig Ziegler Eschscholtz were ethnic Baltic Germans. He studied medicine and zoology at the University of Dorpat and served as an assistant to Carl Friedrich von Ledebour, a professor of botany.McKelvey Eschscholtz received a medical degree in 1815. First voyage On the recommendation of Ledebour, Eschscholtz served as surgeon and naturalist on the Russian expeditionary ship ''Rurik'' under the command of Otto von Kotzebue.Daum (2019) From 1815 to 1818 the expedition circumnavigated the globe for the purposes of seeking a Northwest Passa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus '' Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should cl ... [...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] |
Synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
