Hygrophila is a taxonomic

superorder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

of air-breathing

freshwater snail Freshwater snails are gastropod mollusks that live in fresh water. 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 t ...

s, aquatic

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 inclu ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

s within the clade

Panpulmonata Panpulmonata is a taxonomic clade of snails and slugs in the clade Heterobranchia within the clade Euthyneura. Panpulmonata was established as a new taxon by Jörger et al. in October 2010. The older name "Pulmonata" referred to a group of euth ...

.MolluscaBase eds. (2020). MolluscaBase. Hygrophila. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=382243 on 2020-12-14 The families in this clade are basically air-breathing freshwater snails including freshwater

limpet Limpets are a group of aquatic snails with a conical gastropod shell, shell shape (patelliform) and a strong, muscular foot. This general category of conical shell is known as "patelliform" (dish-shaped). Existing within the class Gastropoda, ...

s. The three families with the greatest number of species are the Lymnaeidae (pond snails), the Planorbidae (ramshorn snails) and the Physidae (pouch or bubble snails). These are found in ponds, creeks, ditches, and shallow lakes nearly worldwide. The snails in this clade have their eyes located at the base of their tentacles, rather than at the tips, as in the true land snails Stylommatophora. They have shells that are thin, translucent, and relatively colorless, and they lack an operculum.

Taxonomy

1997 taxonomy

In the older taxonomy of the Gastropoda (Ponder & Lindberg, 1997) these families were placed in the suborder Basommatophora.

2005 taxonomy

Hygrophila has been a clade in the informal group

Basommatophora Basommatophora was a term that was previously used as a taxonomic informal group, a group of snails within the informal group Pulmonata, the air-breathing slugs and snails. According to the taxonomy of the Gastropoda (Bouchet & Rocroi, 2005), w ...

within the Pulmonata. Clade Hygrophila: *Superfamily Chilinoidea Dall, 1870 **Family Chilinidae Dall, 1870 **Family Latiidae Hutton, 1882 *Superfamily Acroloxoidea Thiele, 1931 **Family

Acroloxidae Acroloxidae, commonly known as river limpets, are a Taxonomy (biology), taxonomic family of very small, freshwater snails, Aquatic animal, aquatic pulmonate gastropod limpet-like mollusks with a simple flattened conical gastropod shell, shell in ...

Thiele, 1931 *Superfamily Lymnaeoidea Rafinesque, 1815 **Family

Lymnaeidae Lymnaeidae, common name the pond snails, is a Taxonomy (biology), taxonomic family (biology), family of small to large air-breathing freshwater snails, Aquatic animal, aquatic pulmonate gastropod mollusks, that belong to the clade Hygrophila (cl ...

Rafinesque, 1815 *Superfamily Planorboidea Rafinesque, 1815 **Family

Planorbidae Planorbidae, common name the ramshorn snails or ram's horn snails, is a family (biology), family of air-breathing freshwater snails, Aquatic animal, aquatic pulmonate gastropod Mollusca, molluscs. Unlike most molluscs, the blood of ram's horn sn ...

Rafinesque, 1815 **Family Physidae Fitzinger, 1833 Note: what was previously the family Ancylidae has been demoted in the new taxonomy to the status of tribe Ancylini Rafinesque, 1815 within the subfamily Planorbinae Rafinesque, 1815 of the family

Rafinesque, 1815.

2010 taxonomy

Basommatophora ( Siphonarioidea and Amphiboloidea and Hygrophila) have been found

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

and so Jörger et al. (2010)Jörger K. M., Stöger I., Kano Y., Fukuda H., Knebelsberger T. & Schrödl M. (2010). "On the origin of Acochlidia and other enigmatic euthyneuran gastropods, with implications for the systematics of Heterobranchia". ''

BMC Evolutionary Biology ''BMC Ecology and Evolution'' (since January 2021), previously ''BMC Evolutionary Biology'' (2001–2020), is a peer-reviewed open access scientific journal covering all fields of evolutionary biology, including phylogenetics and palaeontology ...

'' 10: 323. . have moved Hygrophila to

2020 taxonomy

A comprehensive molecular phylogenetic analysis of Hygrophila based on 3112 sites of the large subunit and 5.8S

ribosomal RNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal ...

genes resulted in a proposal of a new taxonomic revision of the group. * Chilinoidea Dall, 1870 * Lymnaeoidea Rafinesque, 1815 ;Synonyms: * Acroloxoidea Thiele, 1931: synonym of Lymnaeoidea Rafinesque, 1815 * Planorboidea Rafinesque, 1815: synonym of Lymnaeoidea Rafinesque, 1815

References

{{Taxonbar, from=Q872645 Panpulmonata