''Girardia'' 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 ...

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

planarians belonging to the family Dugesiidae.

Distribution

The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species known to occur naturally in North America, ''Girardia tigrina'' and ''Girardia dorotocephala'', have been introduced in other continents and islands.

Description

Species of ''Girardia'' are very similar to species of other genera of Dugesiidae and few apomorphies that clearly define the genus are known. One of the few exclusive characteristics is the presence of pigment granules in the outer pharyngeal wall. Until 1991 ''Girardia'' was considered a

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

of '' Dugesia'', then it was upgraded to the genus rank. However, some works continued to use the old genus for some ''Girardia'' species, mainly for ''

Girardia dorotocephala ''Girardia dorotocephala'' is a species of dugesiid triclad native to North America. It has been accidentally introduced in Japan.Sluys, R., Kawakatsu, M., Yamamoto, K. (2010). "Exotic freshwater planarians currently known from Japan". ''Belgian ...

'' and '' Girardia tigrina''.

Species

*'' Girardia anceps'' (Kenk, 1930) *'' Girardia anderlani'' (Kawakatsu & Hauser, 1983) *'' Girardia andina'' (Borelli, 1895) *'' Girardia antillana'' (Kenk, 1941) *'' Girardia arenicola'' Hellmann & Leal-Zanchet, 2018 *'' Girardia arimana'' (Hyman, 1957) *'' Girardia arizonensis'' (Kenk, 1975) *''

Girardia arndti ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' Marcus, 1946 *'' Girardia asymmetrica'' Hellmann & Leal-Zanchet, 2020 *'' Girardia aurita'' (Kennel, 1888) *'' Girardia avertiginis'' Sluys, 2005 *''

Girardia azteca ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' (Benazzi & Giannini, 1971) *''

Girardia barbarae ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' (Mitchell & Kawakatsu, 1973) *''

Girardia biapertura ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' Sluys, 1997 *''

Girardia bonaerensis ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' (Moretto, 1996) *''

Girardia bursalacertosa ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' Sluys, 2005 *''

Girardia cameliae ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' (Furhmann, 1912) *''

Girardia canai ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' Curino & Cazzaniga, 1993 *''

Girardia capacivasa ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' Sluys & Kawakatsu, 2005 *''

Girardia corumbataiensis ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' Morais & Leal-Zanchet, 2021 *''

Girardia chilla ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' (Marcus, 1954) *''

Girardia cubana ''Girardia'' is a genus of freshwater planarians belonging to the family Dugesiidae. Distribution The genus ''Girardia'' is endemic to the Americas, from Argentina to Canada, although most species occur in South America. The only two species kn ...

'' (Codreanu & Balcesco, 1973) *'' Girardia desiderensis'' Souza & Leal-Zanchet, 2016 *''

'' (Woodworth, 1897) *'' Girardia dubia'' (Borelli, 1895) *'' Girardia festae'' (Borelli, 1898) *'' Girardia glandulosa'' (Kenk, 1930) *'' Girardia graffi'' (Weiss, 1909) *'' Girardia guatemalensis'' (Mitchell & Kawakatsu, 1973) *'' Girardia hoernesi'' (Weiss, 1910) *'' Girardia hypoglauca'' (Marcus, 1948) *'' Girardia ibitipoca'' Hellmann & Leal-Zanchet, 2020 *'' Girardia informis'' Sluys & Grant, 2006 *'' Girardia jenkinsae'' (Benazzi & Gourbault, 1977) *'' Girardia jugosa'' Sluys, 2005 *'' Girardia longistriata'' (Furhmann, 1912) *'' Girardia mckenziei'' (Mitchell & Kawakatsu, 1973) *'' Girardia microbursalis'' (Hyman, 1931) *'' Girardia multidiverticulata'' Souza, Morais, Cordeiro & Leal-Zanchet, 2015 *'' Girardia nobrensis'' Morais & Leal-Zanchet, 2021 *'' Girardia nonatoi'' (Marcus, 1946) *'' Girardia paramensis'' (Fuhrmann, 1912) *'' Girardia paucipunctata'' Hellmann & Leal-Zanchet, 2018 *'' Girardia pierremartini'' Souza & Leal-Zanchet, 2016 *'' Girardia polyorchis'' (Fuhrmann, 1912) *'' Girardia rincona'' (Marcus, 1954) *'' Girardia sanchezi'' (Hyman, 1955) *'' Girardia schubarti'' (Marcus, 1946) *'' Girardia seclusa'' (de Beauchamp, 1940) *'' Girardia sinensis'' Chen & Wang, 2015 *'' Girardia somuncura'' Lenguas Francavilla, Negrete, Martínez-Aquino, Damborenea & Brusa, 2021 *'' Girardia spelaea'' Hellmann & Leal-Zanchet, 2020 *'' Girardia sphincter'' Sluys & Kawakatsu, 2001 *'' Girardia striata'' (Weiss, 1910) *'' Girardia tahitiensis'' Gourbault, 1977 *'' Girardia tigrina'' (Girard, 1850) *'' Girardia tomasi'' Lenguas Francavilla, Negrete, Martínez-Aquino, Damborenea & Brusa, 2021 *'' Girardia titicacana'' (Hyman, 1939) *'' Girardia typhlomexicana'' (Mitchell & Kawakatsu, 1973) *'' Girardia ururiograndeana'' (Kawakatsu, Hauser & Ponce de Leon, 1992)

Phylogeny

Phylogenetic tree including five dugesiid genera after Álvarez-Presas et al., 2008:

References

{{Taxonbar, from=Q5564174 Dugesiidae Rhabditophora genera Animals described in 1974