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Somatogyrus Nanus
The dwarf pebblesnail (''Somatogyrus nanus)'' is a species of very small or minute freshwater snail with an operculum, an aquatic gastropod mollusk in the family Hydrobiidae. This species is endemic to the United States. Its natural habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ... is rivers. References Molluscs of the United States Somatogyrus Gastropods described in 1904 Taxonomy articles created by Polbot {{Hydrobiidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryant Walker
Bryant Walker (1856–1936) was an American malacologist who specialized in the non-marine Mollusca. He mainly studied the freshwater mollusks of the USA, in particular those of Michigan. He published many papers on the Unionida, an order of freshwater mussels. Taxa Walker named numerous taxa of freshwater gastropods and bivalves, including: Gastropods *''Neoplanorbis carinatus'' Walker, 1908 *†''Neoplanorbis smithi †''Neoplanorbis smithi'' was a species of small freshwater snail, an aquatic gastropod mollusk in the family Planorbidae, the ramshorn snails. This species was endemic to the United States; it is now extinct Extinction is the terminati ...'' Walker, 1908 Publications A partial list of his publications*Ortmann, A.E., and B. Walker 1912. A new North American naiad. Nautilus 25(9):97-100 + 1 plate. *Ortmann, A.E., and B. Walker 1922. A new genus and species of American naiades. Nautilus 36(1):1-6 + 1 plate. *Ortmann, A.E., and B. Walker. 1922. On the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of Taxonomy (biology), 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 reproduction, produce Fertility, fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), 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 binomial nomenclature, 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 specifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Snail
Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs to major rivers. The great majority of freshwater gastropods have a shell, with very few exceptions. Some groups of snails that live in freshwater respire using gills, whereas other groups need to reach the surface to breathe air. In addition, some are amphibious and have both gills and a lung (e.g. '' Ampullariidae''). Most feed on algae, but many are detritivores and some are filter feeders. According to a 2008 review of the taxonomy, there are about 4,000 species of freshwater gastropods (3,795–3,972). At least 33–38 independent lineages of gastropods have successfully colonized freshwater environments. It is not possible to quantify the exact number of these lineages yet, because they have yet to be clarified within the Ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (gastropod)
The operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Late Cambrian. , 721 families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently extant with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species. The anatomy, behavior, feeding, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrobiidae
Hydrobiidae, commonly known as mud snails, is a large cosmopolitan family of very small freshwater and brackish water snails with an operculum; they are in the order Littorinimorpha. Distribution Hydrobiidae are found in much of the world, inhabiting all continents except Antarctica. In Australia alone there are over 260 species in the family. Description These are very small or minute snails, with a shell height of less than 8 mm. The dextrally-coiled shells are smooth (except for growth lines conforming to the shape of the outer lip) and are usually rather nondescript. The shell offers very few robust characteristics to the systematist who is attempting to classify the species within this family. This difficulty is compounded by a high degree of intraspecific variation. Descriptions often have to be based on the characteristics of the operculum, radula and penis. The shell of species within this family varies from planispiral to needle-shaped. The shell may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example ''Cytisus aeolicus'' is an endemite of the Italian flora. ''Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical manifestation of its ecological niche. Thus "habitat" is a species-specific term, fundamentally different from concepts such as environment or vegetation assemblages, for which the term "habitat-type" is more appropriate. The physical factors may include (for example): soil, moisture, range of temperature, and light intensity. Biotic factors will include the availability of food and the presence or absence of predators. Every species has particular habitat requirements, with habitat generalist species able to thrive in a wide array of environmental conditions while habitat specialist species requiring a very limited set of factors to survive. The habitat of a species is not necessarily found in a geographical area, it can be the interior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molluscs Of The United States
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gastropo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatogyrus
''Somatogyrus'' is a genus of very small freshwater and brackish water snails that have an operculum, aquatic gastropod micromolluscs in the family Lithoglyphidae. Species Species within the genus ''Somatogyrus'' include: * Reverse pebblesnail, '' Somatogyrus alcoviensis'' * '' Somatogyrus aldrichi'' (W) * Ouachita pebblesnail, '' Somatogyrus amnicoloides'' * Golden pebblesnail, ''Somatogyrus aureus'' * Angular pebblesnail, '' Somatogyrus biangulatus'' * Knotty pebblesnail, ''Somatogyrus constrictus'' * Coosa pebblesnail, ''Somatogyrus coosaensis'' * Thick-lipped pebblesnail, ''Somatogyrus crassilabris'' * Stocky pebblesnail, ''Somatogyrus crassus'' * Tennessee pebblesnail, ''Somatogyrus currierianus'' * Hidden pebblesnail, ''Somatogyrus decipiens'' * Sandbar pebblesnail, '' Somatogyrus depressus'' * Ovate pebblesnail, '' Somatogyrus excavatus'' * Cherokee pebblesnail, '' Somatogyrus georgianus'' * Fluted pebblesnail, '' Somatogyrus hendersoni'' * Granite pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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