''Planorbella'' 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 freshwater air-breathing

snail A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastro ...

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 includ ...

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 Planorbidae, common name the ramshorn snails or ram's horn snails, is a family of air-breathing freshwater snails, aquatic pulmonate gastropod molluscs. Unlike most molluscs, the blood of ram's horn snails contains iron-based hemoglobin ins ...

, the

ram Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch * Ra ...

's horn snails, or planorbids, which all have

sinistral Sinistral and dextral, in some scientific fields, are the two types of chirality ("handedness") or relative direction. The terms are derived from the Latin words for "left" (''sinister'') and "right" (''dexter''). Other disciplines use different ...

, or left-coiling, shells.

Ecology

Species in this genus are sometimes hosts for parasites, constituting a link in the pathway of infection for higher animals. For example, some species of ''Planorbella'' host rediae and

cercariae Trematodes are parasitic flatworms of the class ''Trematoda'', specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secr ...

stages of the parasite ''

Ribeiroia ''Ribeiroia'' () is a genus of trematode parasites that sequentially infect freshwater snails in the family Planorbidae (ramshorn snails) as first intermediate hosts, fish and larval amphibians as second intermediate hosts, and birds and mammals ...

'', prior to ultimate infection of the

Rough-skinned Newt The rough-skinned newt or roughskin newt (''Taricha granulosa'') is a North American newt known for the strong toxin exuded from its skin. Appearance A stocky newt with rounded snout, it ranges from light brown to olive or brownish-black on t ...

. ''Planorbella'' are often

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

grazers, and in some locations such as

oligotroph An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments. Oligotrophs are characterized by slow growth, low rates of ...

slough Slough () is a town and unparished area in the unitary authority of the same name in Berkshire, England, bordering west London. It lies in the Thames Valley, west of central London and north-east of Reading, at the intersection of the M4 ...

s, they may be a dominant element of total ecosystem biomass and hence system integrity.

Species

Species within the genus ''Planorbella'' include: * '' Planorbella ammon'' (Gould, 1855) * '' Planorbella binneyi'' (Tryon, 1867) * '' Planorbella campanulata'' (Say, 1821) * '' Planorbella columbiensis'' (F. C. Baker, 1945) * '' Planorbella corpulenta'' (Say, 1824) * ''

Planorbella duryi ''Planorbella duryi'', common name the Seminole rams-horn, is a species of air-breathing freshwater snail, a pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails. The species is endemic to Florida and is found frequently ...

'' (Wetherby, 1879) * '' Planorbella magnifica'' (Pilsbry, 1903) * † '' Planorbella multivolvis'' (Case, 1847)Bogan A. E. (2000)
''Planorbella multivolvis''2006 IUCN Red List of Threatened Species.
Downloaded on 7 August 2007. * '' Planorbella occidentalis'' (J. G. Cooper, 1870) * '' Planorbella oregonensis'' (Tryon, 1865) * '' Planorbella pilsbryi'' (F. C. Baker, 1926) * '' Planorbella scalaris'' (Jay, 1839) * '' Planorbella subcrenata'' (Carpenter, 1857) * '' Planorbella tenuis'' (Dunker, 1850) * '' Planorbella traski'' (I. Lea, 1856) * '' Planorbella trivolvis'' (Say, 1817) * '' Planorbella truncata'' (M. Miles, 1861)

References

External links

{{Taxonbar, from=Q3061485 Taxa named by Samuel Stehman Haldeman