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Rissoa Membranacea Var
''Rissoa'' is a genus of minute sea snails, marine (ocean), marine gastropod mollusks or micromollusks in the family (biology), family Rissoidae. The genus was first introduced by M. de Freminville for some small shells observed by M. Antoine Risso, a distinguished naturalist of Nice, France. They were described by M. Demarest in 1814 in the "New Bulletin of the Philomatic Society". Description The soft body of the snail is elongated and spiral. The somewhat prolonged mouth has a proboscis. The tentacles are awl-shaped with the eyes on a small prominence near the base. The foot is oval or elliptical. The species is phytophagous. The conical shell has an elongated Spire (mollusc), spire with its Apex (mollusc), apex nipple-shaped. The size of the shell varies between 1 mm and 8 mm. The Whorl (mollusc), whorls are generally convex-shaped with a distinct suture. The Aperture (mollusc), aperture is ovate, roundish or pear-shaped with its anterior end rounded, the posterio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. 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 taxonomy (biology), 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. Phylogeneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (gastropod)
An 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, including the 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 (mollusc), 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 (mollusc), 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 are not capable of closing the shell aperture. Opercula have sometimes been modifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rissoa Angusticostata
''Rissoa'' is a genus of minute sea snails, marine (ocean), marine gastropod mollusks or micromollusks in the family (biology), family Rissoidae. The genus was first introduced by M. de Freminville for some small shells observed by M. Antoine Risso, a distinguished naturalist of Nice, France. They were described by M. Demarest in 1814 in the "New Bulletin of the Philomatic Society". Description The soft body of the snail is elongated and spiral. The somewhat prolonged mouth has a proboscis. The tentacles are awl-shaped with the eyes on a small prominence near the base. The foot is oval or elliptical. The species is phytophagous. The conical shell has an elongated Spire (mollusc), spire with its Apex (mollusc), apex nipple-shaped. The size of the shell varies between 1 mm and 8 mm. The Whorl (mollusc), whorls are generally convex-shaped with a distinct suture. The Aperture (mollusc), aperture is ovate, roundish or pear-shaped with its anterior end rounded, the posterio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rissoa Alpina
''Rissoa'' is a genus of minute sea snails, marine gastropod mollusks or micromollusks in the family Rissoidae. The genus was first introduced by M. de Freminville for some small shells observed by M. Antoine Risso, a distinguished naturalist of Nice, France. They were described by M. Demarest in 1814 in the "New Bulletin of the Philomatic Society". Description The soft body of the snail is elongated and spiral. The somewhat prolonged mouth has a proboscis. The tentacles are awl-shaped with the eyes on a small prominence near the base. The foot is oval or elliptical. The species is phytophagous. The conical shell has an elongated spire with its apex nipple-shaped. The size of the shell varies between 1 mm and 8 mm. The whorls are generally convex-shaped with a distinct suture. The aperture is ovate, roundish or pear-shaped with its anterior end rounded, the posterior end acute and with the peristome complete. The thin and horny operculum is spirally marked and equa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rissoa Alleryi
''Rissoa alleryi'' is a species of small sea snail, a marine gastropod mollusc or micromollusc in the family Rissoidae Rissoidae is a large family of sea snails. Members of the Rissoidae are very small in size and possess an operculum. Distribution and habitat Rissoidae are found worldwide. They live on sandy or gravel bottoms among algae or marine plants. Th .... Description Distribution References Rissoa Gastropods described in 1972 {{Rissoidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rissoa Alienocurta
''Rissoa'' is a genus of minute sea snails, marine gastropod mollusks or micromollusks in the family Rissoidae. The genus was first introduced by M. de Freminville for some small shells observed by M. Antoine Risso, a distinguished naturalist of Nice, France. They were described by M. Demarest in 1814 in the "New Bulletin of the Philomatic Society". Description The soft body of the snail is elongated and spiral. The somewhat prolonged mouth has a proboscis. The tentacles are awl-shaped with the eyes on a small prominence near the base. The foot is oval or elliptical. The species is phytophagous. The conical shell has an elongated spire with its apex nipple-shaped. The size of the shell varies between 1 mm and 8 mm. The whorls are generally convex-shaped with a distinct suture. The aperture is ovate, roundish or pear-shaped with its anterior end rounded, the posterior end acute and with the peristome complete. The thin and horny operculum is spirally marked and equa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rissoa Albugo
''Rissoa albugo'' is a species of minute sea snail, a marine gastropod mollusc or micromollusc in the family Rissoidae Rissoidae is a large family of sea snails. Members of the Rissoidae are very small in size and possess an operculum. Distribution and habitat Rissoidae are found worldwide. They live on sandy or gravel bottoms among algae or marine plants. Th .... Description Distribution References Rissoa Gastropods described in 1873 {{Rissoidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rissoa Aethiopica
''Rissoa'' is a genus of minute sea snails, marine gastropod mollusks or micromollusks in the family Rissoidae. The genus was first introduced by M. de Freminville for some small shells observed by M. Antoine Risso, a distinguished naturalist of Nice, France. They were described by M. Demarest in 1814 in the "New Bulletin of the Philomatic Society". Description The soft body of the snail is elongated and spiral. The somewhat prolonged mouth has a proboscis. The tentacles are awl-shaped with the eyes on a small prominence near the base. The foot is oval or elliptical. The species is phytophagous. The conical shell has an elongated spire with its apex nipple-shaped. The size of the shell varies between 1 mm and 8 mm. The whorls are generally convex-shaped with a distinct suture. The aperture is ovate, roundish or pear-shaped with its anterior end rounded, the posterior end acute and with the peristome complete. The thin and horny operculum is spirally marked and equa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homonym (biology)
In biology, a homonym is a name for a taxon that is identical in spelling to another such name, that belongs to a different taxon. The rule in the International Code of Zoological Nomenclature is that the first such name to be published is the senior homonym and is to be used (it is "valid name (zoology), valid"); any others are junior homonyms and must be replaced with new names. It is, however, possible that if a senior homonym is archaic, and not in "prevailing usage," it may be declared a ''nomen oblitum'' and rendered unavailable, while the junior homonym is preserved as a ''nomen protectum''. :For example: :*Georges Cuvier, Cuvier proposed the genus ''Echidna'' in 1797 for the echidna, spiny anteater. :*However, Johann Reinhold Forster, Forster had already published the name ''Echidna'' in 1777 for a genus of moray eels. :*Forster's use thus has Priority (biology), priority, with Cuvier's being a junior homonym. :*Johann Karl Wilhelm Illiger, Illiger published the replace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rissoa Acuticosta
''Rissoa'' is a genus of minute sea snails, marine gastropod mollusks or micromollusks in the family Rissoidae. The genus was first introduced by M. de Freminville for some small shells observed by M. Antoine Risso, a distinguished naturalist of Nice, France. They were described by M. Demarest in 1814 in the "New Bulletin of the Philomatic Society". Description The soft body of the snail is elongated and spiral. The somewhat prolonged mouth has a proboscis. The tentacles are awl-shaped with the eyes on a small prominence near the base. The foot is oval or elliptical. The species is phytophagous. The conical shell has an elongated spire with its apex nipple-shaped. The size of the shell varies between 1 mm and 8 mm. The whorls are generally convex-shaped with a distinct suture. The aperture is ovate, roundish or pear-shaped with its anterior end rounded, the posterior end acute and with the peristome complete. The thin and horny operculum is spirally marked and equa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
