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Marstonia Arga
''Marstonia'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae. Distribution Species in the genus ''Marstonia'' are distributed in springs, streams and lakes in eastern North America. Most of these species have extremely narrow geographic ranges and consequently have become a focus of conservation activities; two are federally listed as endangered and others are variously listed by state wildlife agencies. Description The freshwater gastropod genus ''Marstonia'' is composed of 15 small (shell height < 5.0 mm), ovate- to elongate-shelled species. ''Marstonia'' differs from the other eight North American nymphophiline genera in that the (female) oviduct and bursal duct join well in front of (instead of behind) the posterior wall of the . [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marstonia Comalensis
''Marstonia comalensis'' is a species of minute freshwater snail with a gill and an operculum, an aquatic gastropod mollusk or micromollusk in the family Hydrobiidae. It is found in south central Texas, United States. ''Marstonia comalensis'' is large for this genus. It has an ovate-conic, openly umbilicate shell. The penis has a short filament and oblique, squarish lobe bearing a narrow gland along its distal edge. It is well differentiated morphologically from other congeners that have similar shells and penes, and is also genetically divergent relative to those congeners that have been sequenced ( mt COI divergence 3.0–8.5%). This species has often been confused with ''Cincinnatia integra''. Taxonomy In 1906, Henry Augustus Pilsbry and James Ferriss described this species under the name ''Amnicola comalensis'' based on six shells from Comal Creek and the Guadalupe River near New Braunfels, south-central Texas. Pilsbry and Ferriss differentiated this species from '' ... [...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, and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrgulopsis Hershleri
''Pyrgulopsis'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae. Etymology The name ''Pyrgulopsis'' is composed from ''Pyrgula'', another genus of snail, and ''opsis'' = aspect of. Description Generic characters of the genus ''Pyrgulopsis'' are: the shell is minute, conically turreted, somewhat elongated, imperforate and unicarinate. The apex is acute. The aperture is ovate. The edge of the aperture, called the peritreme, is continuous. The operculum is ovate, thin, corneous and spiral, with polar point well forward and approximating the columella. The jaw is thin and membranaceous. The radula is odontophore, with teeth are arranged in transverse rows, according to the formula 3 + 1 + 3. Formula for denticles of rhachidian: . Distribution The distribution of the genus ''Pyrgulopsis'' includes Western and South-western United States. Snails of species in the genus ''Pyrgulopsis'' occur in fresh water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marstonia Hershleri
''Marstonia'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae. Distribution Species in the genus ''Marstonia'' are distributed in springs, streams and lakes in eastern North America. Most of these species have extremely narrow geographic ranges and consequently have become a focus of conservation activities; two are federally listed as endangered and others are variously listed by state wildlife agencies. Description The freshwater gastropod genus ''Marstonia'' is composed of 15 small (shell height < 5.0 mm), ovate- to elongate-shelled species. ''Marstonia'' differs from the other eight North American nymphophiline genera in that the (female) oviduct and bursal duct join well in front of (instead of behind) the posterior wall of the . [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrgulopsis Halcyon
''Pyrgulopsis'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae. Etymology The name ''Pyrgulopsis'' is composed from ''Pyrgula'', another genus of snail, and ''opsis'' = aspect of. Description Generic characters of the genus ''Pyrgulopsis'' are: the shell is minute, conically turreted, somewhat elongated, imperforate and unicarinate. The apex is acute. The aperture is ovate. The edge of the aperture, called the peritreme, is continuous. The operculum is ovate, thin, corneous and spiral, with polar point well forward and approximating the columella. The jaw is thin and membranaceous. The radula is odontophore, with teeth are arranged in transverse rows, according to the formula 3 + 1 + 3. Formula for denticles of rhachidian: . Distribution The distribution of the genus ''Pyrgulopsis'' includes Western and South-western United States. Snails of species in the genus ''Pyrgulopsis'' occur in fresh water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marstonia Halcyon
''Marstonia'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae. Distribution Species in the genus ''Marstonia'' are distributed in springs, streams and lakes in eastern North America. Most of these species have extremely narrow geographic ranges and consequently have become a focus of conservation activities; two are federally listed as endangered and others are variously listed by state wildlife agencies. Description The freshwater gastropod genus ''Marstonia'' is composed of 15 small (shell height < 5.0 mm), ovate- to elongate-shelled species. ''Marstonia'' differs from the other eight North American nymphophiline genera in that the (female) oviduct and bursal duct join well in front of (instead of behind) the posterior wall of the . [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marstonia Castor
''Marstonia castor'', common name the beaver pond marstonia, is a species of very small freshwater snail with a gill and an operculum, an aquatic operculate gastropod mollusc in the family Hydrobiidae. This species was endemic 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 elsew ... to a very limited area of the US state of Georgia, mostly to streams and creeks around Lake Blackshear. The US Fish and Wildlife Service declared this species extinct in December 2017 on the basis that it had not been seen since 2000. It was likely wiped out by groundwater withdrawal, pollution, and urbanization. However, the IUCN Red List still lists it as Critically Endangered. References External links Thompson F. G. & Hershler R. (2002) Two genera of North American freshwater snails: Marstonia Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrgulopsis Arga
''Pyrgulopsis'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae. Etymology The name ''Pyrgulopsis'' is composed from ''Pyrgula'', another genus of snail, and ''opsis'' = aspect of. Description Generic characters of the genus ''Pyrgulopsis'' are: the shell is minute, conically turreted, somewhat elongated, imperforate and unicarinate. The apex is acute. The aperture is ovate. The edge of the aperture, called the peritreme, is continuous. The operculum is ovate, thin, corneous and spiral, with polar point well forward and approximating the columella. The jaw is thin and membranaceous. The radula is odontophore, with teeth are arranged in transverse rows, according to the formula 3 + 1 + 3. Formula for denticles of rhachidian: . Distribution The distribution of the genus ''Pyrgulopsis'' includes Western and South-western United States. Snails of species in the genus ''Pyrgulopsis'' occur in fresh water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marstonia Arga
''Marstonia'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae. Distribution Species in the genus ''Marstonia'' are distributed in springs, streams and lakes in eastern North America. Most of these species have extremely narrow geographic ranges and consequently have become a focus of conservation activities; two are federally listed as endangered and others are variously listed by state wildlife agencies. Description The freshwater gastropod genus ''Marstonia'' is composed of 15 small (shell height < 5.0 mm), ovate- to elongate-shelled species. ''Marstonia'' differs from the other eight North American nymphophiline genera in that the (female) oviduct and bursal duct join well in front of (instead of behind) the posterior wall of the . [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marstonia Agarhecta
''Marstonia agarhecta'', common name Ocmulgee marstonia, is a species of freshwater snail with a gill and an operculum, aquatic gastropod mollusk in the family Hydrobiidae. This species is endemic to Georgia, the United States. Its natural habitat is rivers. It is threatened by habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby .... References Molluscs of the United States Hydrobiidae Gastropods described in 1969 Taxonomy articles created by Polbot {{Hydrobiidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smithsonian Contributions To Zoology
The Smithsonian Contributions and Studies Series is a collection of serial periodical publications produced by the Smithsonian Institution, detailing advances in various scientific and societal fields to which the Smithsonian Institution has made contributions. History The Smithsonian Institution began publishing consolidated compilations of quarto-sized papers in 1848, under the name ''Smithsonian Contributions to Knowledge''.History of Scholarly Publishing , ''''. In 1862 -sized papers called ''Smithsonian Miscellaneous Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrgulopsis
''Pyrgulopsis'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae. Etymology The name ''Pyrgulopsis'' is composed from ''Pyrgula'', another genus of snail, and ''opsis'' = aspect of. Description Generic characters of the genus ''Pyrgulopsis'' are: the shell is minute, conically turreted, somewhat elongated, imperforate and unicarinate. The apex is acute. The aperture is ovate. The edge of the aperture, called the peritreme, is continuous. The operculum is ovate, thin, corneous and spiral, with polar point well forward and approximating the columella. The jaw is thin and membranaceous. The radula is odontophore, with teeth are arranged in transverse rows, according to the formula 3 + 1 + 3. Formula for denticles of rhachidian: . Distribution The distribution of the genus ''Pyrgulopsis'' includes Western and South-western United States. Snails of species in the genus ''Pyrgulopsis'' occur in fresh water and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
