Freshwater snail

According to a 2008 review of the taxonomy, there are about 4,000 species of freshwater gastropods (3,795–3,972). The following cladogram is an overview of the main clades of gastropods based on the taxonomy of Bouchet & Rocroi (2005), modified after Jörger et al. (2010) and simplified with families that contain freshwater species marked in boldface: • Neritidae — largely confined to the tropics, also the rivers of Europe, family includes the marine "nerites". There are about 110 extant freshwater species. • Thiaridae — high-spired parthenogenic snails of the tropics, includes those referred to as "trumpet snails" in aquaria. Other species are marine. • Amnicolidae — about 200 species. • Tantulidae — there is only one species which is shell-less Tantulum elegans. ;Pulmonata, Basommatophora Basommatophorans are pulmonate or air-breathing aquatic snails, characterized by having their eyes located at the base of their tentacles, rather than at the tips, as in the true land snails Stylommatophora. The majority of basommatophorans have shells that are thin, translucent, and relatively colorless, and all five freshwater basommatophoran families lack an operculum. • Chilinidae — small to medium-sized snails confined to temperate and cold South America. About 15 species. • Latiidae — small limpet-like snails confined to New Zealand. One or three species. • Acroloxidae — about 40 species. • Lymnaeidae — found worldwide, but are most numerous in temperate and northern regions. These are the dextral (right-handed) pond snails. About 100 species. • Planorbidae — "rams horn" snails, with a worldwide distribution. About 250 species. • Physidae — left-handed (sinistral) "pouch snails", native to Europe, Asia, North America. About 80 species. File:Acroloxus lacustris A MRKVICKA.JPG|Family Acroloxidae, Acroloxus lacustris. File:Water snail Rex 2.jpg|Family Lymnaeidae, Lymnaea stagnalis. File:Physa acuta 001.JPG|Family Physidae, Physella acuta. File:Posthornschnecke1.jpg|Family Planorbidae, Planorbarius corneus. ==Sexual reproduction and self-fertilization==

The freshwater snail Physa acuta is in the subclass Heterobranchia and the family Physidae. P. acuta is a self-fertile snail that can undergo either sexual reproduction or self-fertilization. experimentally tested whether accumulation of deleterious mutations is avoided either by inbreeding populations of the snail (undergoing self-fertilization), or in outbreeding populations undergoing sexual reproduction. Inbreeding promotes the homozygous expression of deleterious recessive mutations in progeny that then exposes these mutations to selective elimination because of their deleterious affects on progeny. Outbreeding sexual reproduction allows females to choose male mating partners with smaller mutation loads that then also leads to a reduction of deleterious mutations in progeny. On the basis of their findings, Noel et al. concluded that both outbred and inbred populations of P. acuta can efficiently eliminate deleterious mutations. == As human food ==

Several different freshwater snail species are eaten in Asian cuisine. Archaeological investigations in Guatemala have revealed that the diet of the Maya of the Classic Period (AD 250–900) included freshwater snails. File:A plate of cooked river snails.jpg|A dish of cooked freshwater snails, ampullariids and viviparids from Poipet, Cambodia File:Gugli chorchori 2017-01-22 122613.jpg|A Bengali dish of stir-fried freshwater snails with onion and garlic paste and other spices, from Kolkata, West Bengal, India == Aquarium snails ==

Freshwater snails are commonly found in aquaria along with tropical fish. Species available vary in different parts of the world. In the United States, commonly available species include ramshorn snails such as Planorbella duryi, bladder snails such as Physella acuta, apple snails such as Pomacea bridgesii, the high-spired thiarid Malaysian trumpet snail, Melanoides tuberculata, and several Neritina species. == Parasitology ==

species which have freshwater snails as intermediate hosts Freshwater snails are widely known to be hosts in the lifecycles of a variety of human and animal parasites, particularly trematodes (or "flukes"). Some of these relations for prosobranch snails include Oncomelania in the family Pomatiopsidae as hosts of Schistosoma, and Bithynia, Parafossarulus and Amnicola as hosts of Opisthorchis. Basommatophoran snails are even more widely infected, with many Biomphalaria (Planorbidae) serving as hosts for Schistosoma mansoni, Fasciolopsis and other parasitic groups. The term "neglected tropical diseases" applies to all snail-borne infections, including schistosomiasis, fascioliasis, fasciolopsiasis, paragonimiasis, opisthorchiasis, clonorchiasis, and angiostrongyliasis. ==See also==