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Calliclava Alcmene
''Calliclava alcmene'' is a species of sea snail, a marine gastropod mollusk in the family (biology), family Drilliidae. Description The size of an adult shell varies between 13.5 mm and 19 mm. (Original description) The small shell is pinkish white and polished. It is acute, with a flat-topped protoconch of two polished, prominently peripherally keeled Whorl (mollusc), whorls and about eight subsequent whorls. The suture is appressed, with a retractively nodulous, thickened band in front of it, forming the posterior margin of the anal fasciole. The Sculpture (mollusc), sculpture consists of (on the body whorl 22) somewhat sigmoid rounded ribs with subequal interspaces, reaching from the suture over the whorl to the siphonal canal. They are constricted over the narrow anal fasciole and feebler on the anterior part of the body whorl. These ribs are cut into subnodulous segments by deep narrow sharp spiral grooves, with much wider interspaces, two or three on the Spire ( ... [...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] |
