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Alcadia Mammilla
''Alcadia mammilla'' is a species of an operculate land snail, terrestrial gastropod mollusk in the family Helicinidae. Description The height of the shell attains , its greatest diameter . (Original description in Latin) The conical shell is rather solid and slightly striated. it is scarcely shiny, with various marbling and banding in whitish and reddish hues. The spire has a convex-conical shape, ending in a pale apex. There are 5 somewhat convex whorls, with the body whorl deflected at the front and slightly flattened at the base. The columella is short and thread-like, ending at the base with a small denticle and emitting a thin callus. The aperture is oblique and somewhat triangular-semioval. The peristome is thin, with the right margin simple at the top, then dilated and expanded, featuring a distinct sinus at the base separated from the columellar tooth. Distribution This species occurs in the Haiti Haiti, officially the Republic of Haiti, is a country on the islan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
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. It is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), morphology, behaviour, or ecological niche. In addition, palaeontologists 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. About 14% of these had been described by 2011. All species (except viruses) are given a binomial nomenclature, two-part name, a "binomen". The first part of a binomen is the name of a genus to which the species belongs. The second part is called the specific name (zoology), specific name or the specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Whorl
The body whorl is part of the morphology (biology), morphology of the gastropod shell, shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the body whorl, or last whorl, is the most recently formed and largest Whorl (mollusc), whorl (or revolution) of a spiral or Helix, helical Gastropod shell, shell, terminating in the Aperture (mollusc), aperture. It is called the "body whorl" because most of the body of the soft parts of the animal fits into this whorl. The proportional size of the body whorl in gastropod shells differs greatly according to the actual shell morphology. For shells in which the rate of whorl expansion of each revolution around the axis is very high, the aperture and the body whorl are large, and the shell tends to be low Spire (mollusc), spired. The shell of the abalone is a good example of this kind of shell. The opposite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcadia
''Alcadia'' is a genus of tropical and subtropical land snails with an Operculum (gastropod), operculum, terrestrial animal, terrestrial gastropod mollusks in the subfamily Helicininae of the family Helicinidae. MolluscaBase eds. (2024). MolluscaBase. Alcadia J. E. Gray, 1840. Accessed through: World Register of Marine * At: https://www.marinespecies.org/aphia.php?p=taxdetails&id=996448 on 2024-07-24 Description ''Alcadia'' differs from the Helicininae in having a slit in front of the Aperture (mollusc), aperture, into which is fitted the tooth-like process of the Operculum (gastropod), operculum. Species Species within the genus ''Alcadia'' include: * ''Alcadia affinis'' C.B. Adams, 1846 * ''Alcadia alta'' (G. B. Sowerby II, 1866) * ''Alcadia aurantia'' (J. E. Gray, 1824) * ''Alcadia bahamensis'' (L. Pfeiffer, 1862) * ''Alcadia bermudezi'' Aguayo & Jaume, 1957 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haiti
Haiti, officially the Republic of Haiti, is a country on the island of Hispaniola in the Caribbean Sea, east of Cuba and Jamaica, and south of the Bahamas. It occupies the western three-eighths of the island, which it shares with the Dominican Republic. Haiti is the third largest country in the Caribbean, and with an estimated population of 11.4 million, is the most populous Caribbean country. The capital and largest city is Port-au-Prince. Haiti was originally inhabited by the Taíno people. In 1492, Christopher Columbus established the first European settlement in the Americas, La Navidad, on its northeastern coast. The island was part of the Spanish Empire until 1697, when the western portion was Peace of Ryswick, ceded to France and became Saint-Domingue, dominated by sugarcane sugar plantations in the Caribbean, plantations worked by enslaved Africans. The 1791–1804 Haitian Revolution made Haiti the first sovereign state in the Caribbean, the second republic in the Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peristome (gastropod)
In the shell of gastropod mollusks (a snail shell), the lip is the free margin of the peristome (synonym: peritreme) or aperture (the opening) of the gastropod shell. In dextral (right-handed) shells (most snail shells are right-handed), the right side or outer side of the aperture is known as the outer lip (''labrum''). The left side of the aperture is known as the inner lip or columellar lip (''labium'') if there is a pronounced lip there. In those species where there is no pronounced lip, the part of the body whorl that adjoins the aperture is known as the parietal wall. The outer lip is usually thin and sharp in immature shells, and in some adults (e.g. the land snails ''Helicella'' and ''Bulimulus''). However, in some other land snails and in many marine species the outer lip is ''thickened'' (also called ''callused''), or ''reflected'' (turned outwards). In some other marine species it is curled inwards (''inflected''), as in the cowries such as ''Cypraea''. It can also be e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where the head-foot part of the body of the animal emerges for locomotion, feeding, etc. The term ''aperture'' is used for the main opening in gastropod shells, scaphopod shells, and also for ''Nautilus'' and ammonite shells. The word is not used to describe bivalve shells, where a natural opening between the two shell valves in the closed position is usually called a ''gape (bivalve), gape''. Scaphopod shells are tubular, and thus they have two openings: a main anterior aperture and a smaller posterior aperture. As well as the aperture, some gastropod shells have additional openings in their shells for respiration; this is the case in some Fissurellidae (keyhole limpets) where the central smaller opening at the apex (mollusc), apex of the shell is called an orifice, and in the Haliotidae (abalone) where the row of respiratory openings in the shell are also called orifices. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callus (mollusc)
A callus is an anatomical feature that exists in some mollusk shells, a thickened area of shell material that can partly or completely cover the umbilicus, or can be located as a coating on the body whorl near the aperture of the shell (i.e. a parietal callus or columellar callus). It is a hardened deposit of enamel, which varies in coloration and size depending on the species A funiculus (plural: funiculi) is a narrow ridge of callus spiraling from the upper lip into the umbilicus. A callus exists in the shells of various species of gastropods (snails) and also in the shells of several species of ''Nautilus'', a cephalopod. A callum is an anatomical feature of some mature bivalve shells of species in the family Pholadidae Pholadidae, known as piddocks or angelwings, are a family (biology), family of bivalve molluscs similar to a clam. Background Piddocks are unique in that each side of their shells is divided into 2 or 3 separate sections. Furthermore, one of the ..., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columella (gastropod)
The columella (meaning "little column") or (in older texts) pillar is a central anatomical feature of a coiled snail shell, a gastropod shell. The columella is often only clearly visible as a structure when the shell is broken, sliced in half vertically, or viewed as an X-ray image. The columella runs from the apex of the shell to the midpoint of the undersurface of the shell, or the tip of the siphonal canal in those shells which have a siphonal canal. If a snail shell is visualized as a cone of shelly material which is wrapped around a central axis, then the columella more or less coincides spatially with the central axis of the shell. In the case of shells that have an umbilicus (mollusc), umbilicus, the columella is a hollow structure. The columella of some groups of gastropod shells can have a number of plications or folds (the columellar fold, plaits or plicae), which are usually visible when looking to the inner lip into the Aperture (mollusc), aperture of the shell. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral or whorled 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 Cone (geometry), conical tube, the growth of which is coiled into an overall Helix, 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 s ... [...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] |
Apex (mollusc)
In anatomy, an apex (adjectival form: apical) is part of the mollusc shell, shell of a mollusk. The apex is the pointed tip (the oldest part) of the shell of a gastropod, scaphopod, or cephalopod. The apex is used in end-blown conch (instrument), conches. Gastropods The word "apex" is most often used to mean the tip of the spire (mollusc), spire of the shell of a gastropod. The apex is the first-formed, and therefore the oldest, part of the shell. To be more precise, the apex would usually be where the tip of the embryonic shell or protoconch is situated, if that is still present in the adult shell (often it is lost or eroded away). Coiled gastropod shells The phrase apical whorls, or protoconch, means the whorls that constitute the embryonic shell at the apex of the shell, especially when this is clearly distinguishable from the later whorls of the shell, otherwise known as the teleoconch. Comparison of the apical part and the whole shell of ''Otukaia kiheiziebisu'': File:Cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spire (mollusc)
A spire is a part of the coiled shell of molluscs. The spire consists of all of the whorls except for the body whorl. Each spire whorl represents a rotation of 360°. A spire is part of the shell of a snail, a gastropod mollusc, a gastropod shell, and also the whorls of the shell in ammonites, which are fossil shelled cephalopods. In textbook illustrations of gastropod shells, the tradition (with a few exceptions) is to show most shells with the spire uppermost on the page. The spire, when it is not damaged or eroded, includes the protoconch (also called the nuclear whorls or the larval shell), and most of the subsequent teleoconch whorls (also called the postnuclear whorls), which gradually increase in area as they are formed. Thus the spire in most gastropods is pointed, the tip being known as the " apex". The word "spire" is used, in an analogy to a church spire or rock spire, a high, thin, pinnacle. The "spire angle" is the angle, as seen from the apex, at which a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
