''Helicostoa'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus of

freshwater snail Freshwater snails are gastropod mollusks which 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 ...

, an aquatic

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. T ...

mollusc 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 esti ...

in the order

Littorinimorpha Littorinimorpha is a large order of snails, gastropods, consisting primarily of sea snails ( marine species), but also including some freshwater snails ( aquatic species) and land snails (terrestrial species).Bouchet P. & Rocroi J.-P. (Ed.); Fr� ...

containing the single species ''Helicostoa sinensis''. ''Helicostoa'' is also the only genus in the family Helicostoidae.Strong E. E., Gargominy O., Ponder W. F. & Bouchet P. (2008). "Global Diversity of Gastropods (Gastropoda; Mollusca) in Freshwater". ''

Hydrobiologia ''Hydrobiologia'', ''The International Journal of Aquatic Sciences'', is a peer-reviewed scientific journal publishing 21 issues per year, for a total of well over 4000 pages per year. ''Hydrobiologia'' publishes original research, reviews and opi ...

'' 595: 149-166. . According to taxonomy of the Gastropoda by Bouchet & Rocroi (2005) the family Helicostoidae has no subfamilies. ''Helicostoa sinensis'' was previously tentatively placed within the superfamily

Rissooidea Rissooidea, originally named Rissoacea by Gray, 1847, is a taxonomic superfamily of small and minute marine snails, belonging to the clade Littorinimorpha.Gofas, S. (2013). Rissooidea. Accessed through: World Register of Marine Species at htt ...

. and before that it was in the superfamily

Vermetoidea The Vermetoidea, the worm snails or worm shells, are a taxonomic superfamily of small to medium-sized sea snails, marine gastropod molluscs in the order Littorinimorpha.MolluscaBase (2019). MolluscaBase. Vermetoidea Rafinesque, 1815. Accessed th ...

. ''Helicostoa sinensis'' is only found in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

, more specifically in the

Yangtze River The Yangtze or Yangzi ( or ; ) is the longest list of rivers of Asia, river in Asia, the list of rivers by length, third-longest in the world, and the longest in the world to flow entirely within one country. It rises at Jari Hill in th ...

. This freshwater snail lives attached or bonded to blocks of

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

References

{{Taxonbar, from1=Q20679000, from2=Q5705239, from3=Q21293821 Gastropods described in 1926 Monotypic gastropod genera