Freshwater snail

Freshwater snails are gastropod mollusks which live in freshwater. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs to major rivers. The great majority of freshwater gastropods have a shell, with very few exceptions. Some groups of snails that live in freshwater respire using gills, whereas other groups need to reach the surface to breathe air. In addition, some are amphibious and have both gills and a lung (e.g. Ampullariidae). Most feed on algae, but many are detritivors and some are filter feeders.† Paleozoic molluscs of uncertain systematic position† Basal taxa that are certainly GastropodaPatellogastropodaVetigastropodaCocculiniformia† Paleozoic Neritimorpha of uncertain systematic position† CyrtoneritimorphaCycloneritimorpha: Neritiliidae and NeritidaeCaenogastropoda of uncertain systematic positionArchitaenioglossa: Ampullariidae and ViviparidaeSorbeoconcha: Melanopsidae, Pachychilidae, Paludomidae, Pleuroceridae, Semisulcospiridae and ThiaridaeLittorinimorpha: Littorinidae, Amnicolidae, Assimineidae, Bithyniidae, Cochliopidae, Helicostoidae, Hydrobiidae, Lithoglyphidae, Moitessieriidae, Pomatiopsidae and StenothyridaePtenoglossaNeogastropoda: Nassariidae and MarginellidaeLower Heterobranchia: Glacidorbidae and ValvatidaeCephalaspideaThecosomataGymnosomataAplysiomorphaAcochlidiacea: Acochlidiidae, Tantulidae and StrubelliidaeSacoglossaCylindrobullidaUmbraculidaNudipleuraBasommatophora: Chilinidae, Latiidae, Acroloxidae, Lymnaeidae. Planorbidae ► and Physidae - all these six families together form the clade HygrophilaEupulmonata† Paleozoic molluscs of uncertain systematic position† Basal taxa that are certainly GastropodaPatellogastropodaVetigastropodaCocculiniformia† Paleozoic Neritimorpha of uncertain systematic position† CyrtoneritimorphaCycloneritimorpha: Neritiliidae and NeritidaeCaenogastropoda of uncertain systematic positionArchitaenioglossa: Ampullariidae and ViviparidaeSorbeoconcha: Melanopsidae, Pachychilidae, Paludomidae, Pleuroceridae, Semisulcospiridae and ThiaridaeLittorinimorpha: Littorinidae, Amnicolidae, Assimineidae, Bithyniidae, Cochliopidae, Helicostoidae, Hydrobiidae, Lithoglyphidae, Moitessieriidae, Pomatiopsidae and StenothyridaePtenoglossaNeogastropoda: Nassariidae and MarginellidaeLower Heterobranchia: ValvatidaeNudipleuraEuopisthobranchiaGlacidorboidea with the only family GlacidorbidaeHygrophila: Chilinidae, Latiidae, Acroloxidae, Lymnaeidae. Planorbidae ► and PhysidaeAcochlidiacea: Acochlidiidae, Tantulidae and StrubelliidaeEupulmonataFamily Neritidae, shells of Theodoxus fluviatilis.Family Neritidae, Neritina natalensisFamily Ampullariidae, Pomacea bridgesii.Family Viviparidae, Viviparus viviparus.Family Melanopsidae, Melanopsis praemorsaFamily Pleuroceridae, Io fluvialis.Family Semisulcospiridae, Semisulcospira kurodai.Family Thiaridae, Melanoides tuberculata.Family Bithyniidae, Bithynia tentaculata.Family Cochliopidae, Antrobia culveri.Family Helicostoidae, Helicostoa sinensis shells.Family Hydrobiidae, Sadleriana fluminensisFamily Lithoglyphidae, Lithoglyphus naticoides.Family Pomatiopsidae, Oncomelania hupensis.Family Acroloxidae, Acroloxus lacustris.Family Lymnaeidae, Lymnaea stagnalis.Family Physidae, Physella acuta.Family Planorbidae, Planorbarius corneus.A dish of cooked freshwater snails, ampullariids and viviparids from Poipet, CambodiaA Bengali dish of stir-fried freshwater snails with onion and garlic paste and other spices, from Kolkata, West Bengal, India Freshwater snails are gastropod mollusks which live in freshwater. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs to major rivers. The great majority of freshwater gastropods have a shell, with very few exceptions. Some groups of snails that live in freshwater respire using gills, whereas other groups need to reach the surface to breathe air. In addition, some are amphibious and have both gills and a lung (e.g. Ampullariidae). Most feed on algae, but many are detritivors and some are filter feeders. According to a 2008 review of the taxonomy, there are about 4,000 species of freshwater gastropods (3,795-3,972). At least 33–38 independent lineages of gastropods have successfully colonized freshwater environments. It is not possible to quantify the exact number of these lineages yet, because they have yet to be clarified within the Cerithioidea. From six to eight of these independent lineages occur in North America. The following cladogram is an overview of the main clades of gastropods based on the taxonomy of Bouchet & Rocroi (2005), with families that contain freshwater species marked in boldface: (Some of the highlighted families consist entirely of freshwater species, but some of them also contain, or even mainly consist of, marine species.) 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: (Marine gastropods (Siphonarioidea, Sacoglossa, Amphiboloidea, Pyramidelloidea) are not depicted within Panpulmonata for simplification. Some of these highlighted families consist entirely of freshwater species, but some of them also contain, or even mainly consist of, marine species.) The Neritimorpha are a group of primitive 'prosobranch' gilled snails which have a shelly operculum. The Caenogastropoda are a large group of gilled operculate snails, which are largely marine. In freshwater habitats there are ten major families of caenogastropods, as well as several other families of lesser importance: