''Rhodacmea'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of small

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 ...

s or

limpet Limpets are a group of aquatic snails that exhibit a conical shell shape (patelliform) and a strong, muscular foot. Limpets are members of the class Gastropoda, but are polyphyletic, meaning the various groups called "limpets" descended indep ...

s, 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 ...

mollusk 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 e ...

s in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Planorbidae, the ram's horn snails and their allies.Ó Foighil D., Li J., Lee T., Johnson P., Evans R. & Burch J. B. (2011). "Conservation Genetics of a Critically Endangered Limpet Genus and Rediscovery of an Extinct Species". '' PLoS ONE'' 6(5): e20496. . ''Rhodacmea'' is the

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal f ...

of the subfamily Rhodacmeinae.

Anatomy

These animals have a pallial lung, as do all pulmonate snails, but they also have a false gill or "pseudobranch". This serves as a

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

, which is necessary as, in their non-tidal habitat, these limpets never reach the surface for air.

Species

Species in the genus ''Rhodacmea'' include: * '' Rhodacmea elatior'' (Anthony, 1855) – Domed ancylid * '' Rhodacmea filosa'' (Conrad, 1834) –

Wicker ancylid The wicker ancylid (''Rhodacmea filosa'') is a species of small, air-breathing, freshwater snail or limpet, a pulmonate gastropod in the family Planorbidae. ''Rhodacmea filosa'' is the type species of the genus ''Rhodacmea''. Distribution Thi ...

, type species * '' Rhodacmea hinkleyi'' (Walker, 1908)

References

{{Taxonbar, from=Q3073248 Planorbidae Taxonomy articles created by Polbot