|
Helicella Itala
''Helicella itala'' is a species of medium-sized, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Geomitridae, the hairy snails and their allies. MolluscaBase eds. (2021). MolluscaBase. Helicella itala (Linnaeus, 1758). Accessed through: World Register of Marine Species at: http://marinespecies.org/aphia.php?p=taxdetails&id=426387 on 2021-02-01 English common name is Heath snail. ;Subspecies: * ''Helicella itala itala'' (Linnaeus, 1758) * ''Helicella itala pampelonensis'' (A. Schmidt, 1855) Life cycle The size of the egg is 1.5 mm.Heller J.: ''Life History Strategies''. in Barker G. M. (ed.): The biology of terrestrial molluscs'. CABI Publishing, Oxon, UK, 2001, . 1-146, cited page: 428. This species of snail makes and uses love darts during mating. Description The 12–20 mm. shell is broad and very depressed with an open coil forming a convex, low spire. The umbilicus is very wide. The whorls are slightly convex and have sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod Shell
The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less (slugs) but may have a remnant within the mantle, or in some cases the shell is reduced such that the body cannot be retracted within it (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the Aperture (mollusc), aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. Shell layers The gastropod shell has three major layers secreted by the Mantle (mollusc), mantle. The calcareous central layer, tracum, is typically made of calcium carbonate precipitated into an organic matrix known as c ... [...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] |
Palearctic Molluscs
The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa. The realm consists of several bioregions: the Euro-Siberian region; the Mediterranean Basin; the Sahara and Arabian Deserts; and Western, Central and East Asia. The Palaearctic realm also has numerous rivers and lakes, forming several freshwater ecoregions. The term 'Palearctic' was first used in the 19th century, and is still in use as the basis for zoogeographic classification. History In an 1858 paper for the ''Proceedings of the Linnean Society'', British zoologist Philip Sclater first identified six terrestrial zoogeographic realms of the world: Palaearctic, Aethiopian/Afrotropic, Indian/Indomalayan, Australasian, Nearctic, and Neotropical. The six indicated general groupings of fauna, based on shared biogeography and large-scale geographic barriers to migration. Alfred Wallace adop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animalbase
AnimalBase is a project brought to life in 2004 and is maintained by the University of Göttingen, Germany. The goal of the AnimalBase project is to digitize early zoological literature, provide copyright-free open access to zoological works, and provide manually verified lists of names of zoological genera and species as a free resource for the public. AnimalBase contributed to opening up the classical taxonomic literature, which is considered as useful because access to early literature (especially for the late 18th century) can be difficult for researchers who need the old sources for their taxonomic research. AnimalBase data are public domain. The public use of AnimalBase data is not restricted or conditioned.AnimalBase Project Group, 2005-2010. AnimalBase. Early zoological literature online. World wide web electronic publication http://www.animalbase.uni-goettingen.de accessed 30 July 2010. AnimalBase covers all zoological disciplines. In the field of biodiversity informatics A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palearctic
The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa. The realm consists of several bioregions: the Euro-Siberian region; the Mediterranean Basin; the Sahara and Arabian Deserts; and Western, Central and East Asia. The Palaearctic realm also has numerous rivers and lakes, forming several freshwater ecoregions. The term 'Palearctic' was first used in the 19th century, and is still in use as the basis for zoogeographic classification. History In an 1858 paper for the ''Proceedings of the Linnean Society'', British zoologist Philip Sclater first identified six terrestrial zoogeographic realms of the world: Palaearctic, Aethiopian/Afrotropic, Indian/Indomalayan, Australasian, Nearctic, and Neotropical. The six indicated general groupings of fauna, based on shared biogeography and large-scale geographic barriers to migration. Alfred Wallace a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Love Darts
A love dart (also known as a gypsobelum, shooting darts, or just as darts) is a sharp, calcareous or chitinous dart which some hermaphroditic land snails and slugs create. Love darts are both formed and stored internally in a dart sac. These darts are made in sexually mature animals only, and are used as part of the sequence of events during courtship, before actual mating takes place. Darts are quite large compared to the size of the animal: in the case of the semi-slug genus ''Parmarion'', the length of a dart can be up to one fifth that of the semi-slug's foot. The process of using love darts in snails is a form of sexual selection. Prior to copulation, each of the two snails (or slugs) attempts to "shoot" one (or more) darts into the other snail (or slug). There is no organ to receive the dart; this action is more analogous to stabbing, or to being shot with an arrow or flechette. The dart does not fly through the air to reach its target, but is "fired" as a contact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicella Itala Dart
''Helicella'' is a genus of small to medium-sized, air-breathing land snails, terrestrial pulmonate gastropod mollusks in the subfamily Helicellinae of the family Geomitridae, the hairy snails and their allies. MolluscaBase eds. (2021). MolluscaBase. Helicella A. Férussac, 1821. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=153980 on 2021-02-01 Species Species within the genus ''Helicella'' include: , accessed 29 June 2010. * '' Helicella bolenensis'' [...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] |
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] |
Pulmonate
Pulmonata or pulmonates, is an informal group (previously an order, and before that a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includes many land and freshwater families, and several marine families. The taxon Pulmonata as traditionally defined was found to be polyphyletic in a molecular study per Jörger ''et al.'', dating from 2010. Pulmonata are known from the Carboniferous Period to the present. Pulmonates have a single atrium and kidney, and a concentrated, symmetrical, nervous system. The mantle cavity is located on the right side of the body, and lacks gills, instead being converted into a vascularised lung. Most species have a shell, but no operculum, although the group does also include several shell-less slugs. Pulmonates are hermaphroditic, and some groups possess love darts. Linnean taxonomy The taxonomy of this group according to the taxonomy of the Ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrestrial Molluscs
Terrestrial molluscs or land molluscs (mollusks) are an ecological group that includes all molluscs that live on land in contrast to freshwater and marine molluscs. They probably first occurred in the Carboniferous, arising from freshwater ones. Characteristics This group includes land snails and land slugs. Loss of the shell has taken place many times in different groups that are not evolutionarily closely related, and land snails and slugs are most often treated together as a single group in specialized malacological literature.Barker G. M. (ed.) The biology of terrestrial molluscs'. CABI Publishing, 2001, 558 pp. .Barker G. M. (ed.) Natural enemies of terrestrial molluscs'. CABI Publishing, 2004, 644 pp. . All terrestrial molluscs belong to the class Gastropoda. However, colonization of the land took place several times during the evolutionary past, and as a result terrestrial molluscs are classified in several different, often not closely related, gastropod taxa. Terrestr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
