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Clavatula Decorata
''Clavatula decorata'' is a species of sea snail, a marine gastropod mollusk in the family Clavatulidae. Description The length of the shell attains 21 mm, its width 8 mm. (From the original description) The fusiform shell is one of striking character. The spire is acutely turreted and contains 10 whorls. The whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...s are unusually concave, with a stout prominent keel, crossed by numerous oblong somewhat oblique white tubercles or short plicae, which are rendered more conspicuous by a brown intersecting spiral line. Distribution This species occurs in the Atlantic Ocean off Sierra Leone. References {{DEFAULTSORT:Clavatula Decorata decorata Gastropods described in 1916 ... [...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] |
Sea Snail
Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the absence of a visible shell. Definition Determining whether some gastropods should be called sea snails is not always easy. Some species that live in brackish water (such as certain neritids) can be listed as either freshwater snails or marine snails, and some species that live at or just above the high tide level (for example species in the genus '' Truncatella'') are sometimes considered to be sea snails and sometimes listed as land snails. Anatomy Sea snails are a very large group of animals and a very diverse one. Most snails that live in salt water respire using a gill or gills; a few species, though, have a lung, are intertidal, and are active only at low tide when they can move around in the air. These air-breathing species includ ... [...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] |
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 gas ... [...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 opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clavatulidae
Clavatulidae is a taxonomic family of sea snails, marine gastropod mollusks in the superfamily Conoidea. The family is not well differentiated morphologically. Clavatulidae was raised, based on cladistic analysis, from subfamily to the family level by Rosenberg in 1998. It is no longer regarded as a subfamily of Turridae by several malacologists (Kantor, Sysoev).World Register of Marine Species: Clavatulidae accessed 1 April 2010. This family has no subfamilies. General characteristics This family consists of species with a medium-sized to rather large, fusiform shell. The oblong, pointed is rather high. Th ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Molluscan Studies
The ''Journal of Molluscan Studies'' is the peer-reviewed scientific journal of the Malacological Society of London, covering research in malacology.About the journal accessed 6 December 2010. Previous names of this journal include ''Proceedings of the Malacological Society'', and ''Proceedings of the Malacological Society of London'' (abbreviated as ''Proc. Malacol. Soc. Lond.''). Abstracting and indexing The journal is abstracted and indexed by ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in numerous gastropods, but it is also found in shelled cephalopods including ''Nautilus'', ''Spirula'' and the large extinct subclass of cephalopods known as the ammonites. A spiral shell can be visualized as consisting of a long conical tube, the growth of which is coiled into an overall helical or planispiral shape, for reasons of both strength and compactness. The number of whorls which exist in an adult shell of a particular species depends on mathematical factors in the geometric growth, as described in D'Arcy Wentworth Thompson's classic 1917 book ''On Growth and Form'', and by David Raup. The main factor is how rapidly the conical tube expands (or flares-out) over time. When the rate of expansion is low, such that each subsequent whorl is not that much wider than the previous one, then the adult shell has numerous whorls. When the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sierra Leone
Sierra Leone,)]. officially the Republic of Sierra Leone, is a country on the southwest coast of West Africa. It is bordered by Liberia to the southeast and Guinea surrounds the northern half of the nation. Covering a total area of , Sierra Leone has a tropical climate, with diverse environments ranging from savanna to rainforests. The country has a population of 7,092,113 as of the 2015 census. The capital and largest city is Freetown. The country is divided into five administrative regions, which are subdivided into Districts of Sierra Leone, 16 districts. Sierra Leone is a constitutional republic with a unicameral parliament and a directly elected executive president, president serving a five-year term with a maximum of two terms. The current president is Julius Maada Bio. Sierra Leone is a Secular state, secular nation with Constitution of Sierra Leone, the constitution providing for the separation of state and religion and freedom of conscience (which includes freedom of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clavatula
''Clavatula'' is a genus of sea snails, marine gastropod mollusks in the family Clavatulidae. Description In this genus, the shell is fusiform, with a well-produced spire. The whorls are coronated with tubercles or short spines at the suture;. The aperture is oval. The columellar lip is smooth, arcuate, and callous behind. The outer lip is thin and arcuated, with the anal sinus situated below the sutural coronal. The operculum is semioval with its nucleus about the middle, on the inner side. The foot is large, short and obtuse behind. The eyes are placed externally near the extremity of the tentacles. The radula contains a small unicuspid central tooth with single sharp laterals (formula :1-1-1). The species mostly inhabits the west coast of Africa. Species Species within the genus ''Clavatula'' include: * '' Clavatula ahuiri'' Cossignani & Ardovini, 2014 * †'' Clavatula aralica'' (Luković, 1924) (an extinct species from the Eocene in western Kazakhstan (Tshegan Formatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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