Portal:Gastropods
The gastropods portalGastropods (/ˈɡæstrəpɒdz/), commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (/ɡæsˈtrɒpədə/). This class comprises snails and slugs from saltwater, freshwater, and from the land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, land snails and slugs. The class Gastropoda is a diverse and highly successful class of mollusks within the phylum Mollusca. It 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 reproductive adaptations of gastropods vary significantly from one clade or group to another, so stating many generalities for all gastropods is difficult. The class Gastropoda has an extraordinary diversification of habitats. Representatives live in gardens, woodland, deserts, and on mountains; in small ditches, great rivers, and lakes; in estuaries, mudflats, the rocky intertidal, the sandy subtidal, the abyssal depths of the oceans, including the hydrothermal vents, and numerous other ecological niches, including parasitic ones. Although the name "snail" can be, and often is, applied to all the members of this class, commonly this word means only those species with an external shell big enough that the soft parts can withdraw completely into it. Slugs are gastropods that have no shell or a very small, internal shell; semislugs are gastropods that have a shell that they can partially retreat into but not entirely. The marine shelled species of gastropods include species such as abalone, conches, periwinkles, whelks, and numerous other sea snails that produce seashells that are coiled in the adult stage—though in some, the coiling may not be very visible, for example in cowries. In a number of families of species, such as all the various limpets, the shell is coiled only in the larval stage, and is a simple conical structure after that. (Full article...) Selected articleViviparus georgianus, common name the banded mystery snail, is a species of large freshwater snail with gills and an operculum, an aquatic gastropod mollusk in the family Viviparidae. This snail is native to North America. The specific epithet georgianus is a reference to the southern State of Georgia, where the type locality is situated. Viviparus georgianus was originally discovered and described (under the name Paludina georgiana) by Isaac Lea in 1834. This snail is found in lakes and slow-moving rivers with mud bottoms. The species thrives in eutrophic lentic environments such as lakes, ponds and some low-flow streams. It is usually absent from larger, faster flowing rivers; however, it is able to survive conditions of high water velocity in the St. Lawrence River, and in the United States it may even be better adapted than the introduced species Bithynia tentaculata to such habitats. This species is dioecious (it has two distinct sexes), iteroparous (reproducing more than once in a lifetime) and ovoviviparous, laying eggs singly in albumen-filled capsules. (Read more...) Selected biographyStephen Jay Gould (September 10, 1941 – May 20, 2002) was an American paleontologist, evolutionary biologist and historian of science. He was also one of the most influential and widely read writers of popular science of his generation. Gould spent most of his career teaching at Harvard University and working at the American Museum of Natural History in New York City. In the latter years of his life, Gould also taught biology and evolution at New York University near his home in SoHo. Gould's greatest contribution to science was the theory of punctuated equilibrium, which he developed with Niles Eldredge in 1972. Most of Gould's empirical research was based on the land snails Poecilozonites and Cerion, which are endemic to Bermuda and the Caribbean area respectively. Gould also contributed to evolutionary developmental biology, and has received wide praise for his book Ontogeny and Phylogeny. In evolutionary theory he opposed strict selectionism, sociobiology as applied to humans, and evolutionary psychology. He campaigned against creationism and proposed that science and religion should be considered two distinct fields, or "magisteria", whose authorities do not overlap. (Read more...) Did you know?
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Selected imageThe Spanish slug Arion vulgaris (still often incorrectly referred to as Arion lusitanicus) is a large land slug with a body length of up to 12 cm. It is brown in color. This is a highly invasive species and is considered to be the worst European agricultural pest. It belongs to the family Arionidae, the roundback slugs. Species in this family of slugs have the respiratory opening or pneumostome positioned just anterior to the mid-point of the mantle. The pneumostome is visible in this image as a circular opening behind the head on the right-hand side of the slug. The shell of the Spanish slug is completely reduced, existing only as internal microscopic calcareous granules. Lists of gastropods
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Related portalsSubcategoriesCategories about gastropods: Request to editors: please do not create any more categories of gastropods by country. Instead create list articles, article with a list of the marine or non-marine gastropods of whichever country or area you are interested in. We would also like to empty and delete the two remaining country categories we have, adding that information to list articles instead. Thank you. Things to do
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