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Pleurotomella Lucasii
''Pleurotomella lucasii'' is a species of sea snail, a marine gastropod mollusk in the family (biology), family Raphitomidae. Description The length of the shell attains 10 mm, its diameter 4.5 mm. This fusiform species is more effuse and inflated than its congeners. The shell contains 9 whorls including 4 apical whorls. The apical whorls are beautifully decussate. The whorls of the teleoconch are ventricose. The conspicuous spiral, raised lirae (7 at the penultimate whorl, 18 on the body whorl) extend at unequal intervals over the whole surface of the lower Whorl (mollusc), whorls. They are almost unbroken on the ventricose body whorl, while crossed frequently above by irregular liral riblets on the upper whorls. The Aperture (mollusc), aperture is rotund-ovate. The outer Lip (gastropod), lip is very effuse. The recurved siphonal canal is slightly produced. The shell is hardly shining and shows dark brown spots. [...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] |
