Lymnaeidae


Lymnaeidae, common name the pond snails, is a taxonomic family of small to large air-breathing freshwater snails, aquatic pulmonate gastropod mollusks, that belong to the clade Hygrophila.
Lymnaeidae is the only family within the superfamily Lymnaeoidea.

Taxonomy

2005 taxonomy

Bouchet & Rocroi recognized four subfamilies within Lymnaeidae:
  • subfamily Lymnaeinae Rafinesque, 1815 - synonyms: Amphipepleinae Pini, 1877; Limnophysidae W. Dybowski, 1903; Acellinae Hannibal, 1912; Fossariinae B. Dybowski 1913
  • subfamily Lancinae Hannibal, 1914
  • † subfamily Scalaxinae Zilch, 1959
  • † subfamily Valencieniinae Kramberger-Gorjanovic, 1923 - synonym: Clivunellidae Kochansky-Devidé & Sliskovic, 1972

2013 taxonomy

Vinarski established a new subfamily Radicinae within Lymnaeidae, but be considered position neither of Lancinae nor of extinct genera.
  • subfamily Radicinae Vinarski, 2013

Cladogram

Correa et al. examined phylogenetic relationships among 50 taxa of this family using a supermatrix approach involving both maximum likelihood and Bayesian inference. Her phylogenetic analysis demonstrates the existence of three deep clades of Lymnaeidae representing the main geographic origin of species. It demonstrates that the nomenclature of most genera in the Lymnaeidae does not reflect evolutionary relationships.
A cladogram based on sequences of 16S, internal transcribed spacers ITS1 and ITS2 genes showing phylogenic relations of Lymnaeidae by Correa et al. :
The nomenclature of genera has been one of the most confusing issues in the Lymnaeidae systematics. Most genus names are not fixed and are based more on phenotypic resemblances than on sound evolutionary and phylogenetic considerations. For instance, a single genus in Lymnaeidae was recognized by Walter, two by Hubendick, and up to 34 genera by others. Results by Correa et al. indicate that genera in Lymnaeidae do not reflect phylogenetic relationships, to the notable exception of Radix.
The type species of Lymnaea is Lymnaea stagnalis Linnaeus, 1758; the type species of Stagnicola Jeffreys, 1830 is Stagnicola palustris ; and the type species of Omphiscola Rafinesque, 1819 is Omphiscola glabra. However, it is clear that these three species belong to the same clade and that Lymnaea is not a monophyletic group. Correa et al. proposed that species of clade C2 should all be called Lymnaea, according to the principle of priority of the International Code of Zoological Nomenclature. By extension, Stagnicola should not be used to name species in clade C1a since the type species belongs to clade C2. Meier-Brook & Bargues suggested including Stagnicola emarginata, Stagnicola elodes, Stagnicola catascopium and Lymnaea occulta within a new genus Catascopia, while Stagnicla caperata would belong to the genus Hinkleyia Baker, 1928. The phylogeny by Correa et al. does not conflict with this nomenclature, although it would seem preferable to identify all species of clade C1a with the same name to reflect the close evolutionary relationships among these species. Hinkleyia would be the preferable name according to the ICZN. On the other hand, at least four genera names have been used for species of clade C1b: Lymnaea Lamarck, 1799; Galba Schrank, 1803; Fossaria Westerlund, 1885; and Bakerilymnaea. In the light of the present results, it would be preferable to unify nomenclature. According to the ICZN, Lymnaea should be the unified name, but given that the type species belongs to clade C2, Galba could be a more appropriate name. Finally, as said above, Austropeplea Cotton, 1942 is not a monophyletic group, and employing the genus Kutikina Ponder & Waterhouse, 1997 seems unjustified on the basis of the current phylogeny. This would also be consistent with results of Puslednik et al.. It would be preferable to use Bullastra Pfeiffer, 1839 for all species of clade C3a to fit the ICZN.

Genera

Genera in the family Lymnaeidae include:
subfamily LymnaeinaeAcella Haldeman, 1841Aenigmomphiscola Kruglov & Starobogatov, 1981Bulimnea Haldeman, 1841Corvusiana Servain, 1881 - probably a subgenus of Stagnicola
  • * subgenus Corvusiana sensu stricto
  • * subgenus Kuesterilymnaea Vinarski, 2003Erinna H. Adams & A. Adams, 1858Galba Schrank, 1803 - synonym: Fossaria Westerlund, 1885
  • * subgenus Galba sensu stricto
  • * subgenus Bakerilymnaea Weyrauch, 1964
  • * subgenus Sibirigalba Kruglov et Starobogatov, 1985Hinkleyia F. C. Baker, 1928Ladislavella B. Dybowski, 1913 - synonym: Catascopia Meier-Brook & Bargues, 2002
  • * subgenus Lymnaea sensu stricto
  • * subgenus Kazakhlymnaea Kruglov & Starobogatov, 1984Lymnaea Lamarck, 1799 - type genus of the family LymnaeidaeOmphiscola Rafinesque, 1819Pseudoisidora Thiele, 1931
  • * subgenus Pseudoisidora sensu stricto
  • * subgenus Pseudobulinus Kruglov & Starobogatov, 1993Pseudosuccinea F. C. Baker, 1908Sphaerogalba Kruglov & Starobogatov, 1985 - possibly a synonym of BakerilymnaeaStagnicola Leach in Jeffreys, 1830Walhiana Servain, 1881 - probably a subgenus of StagnicolaWalterigalba Kruglov & Starobogatov, 1985 - probably a subgenus of Hinkleyia
;Genera brought into synonymy:Catascopia Meier-Brook & Bargues, 2002: synonym of Ladislavella B. Dybowski, 1913Fossaria Westerlund, 1885: synonym of Galba Schrank, 1803Limnaea: synonym of Lymnaea Lamarck, 1799Limneus Sandberger, 1875: synonym of Lymnaea Lamarck, 1799Limneus auct.: synonym of Lymnaea Lamarck, 1799Limnophysa Fitzinger, 1833: synonym of Stagnicola Jeffreys, 1830Lymnaeus: synonym of Lymnaea Lamarck, 1799Nasonia F. C. Baker, 1928: synonym of Galba Weyrauch, 1964 represented as Galba Schrank, 1803Truncatuliana Servain, 1881: synonym of Galba Schrank, 1803Walterlymnaea Starobogatov & Budnikova, 1976: synonym of Ladislavella B. Dybowski, 1913
subfamily Amphipepleinae Pini, 1877 Austropeplea B. C. Cotton, 1942 - synonym: Kutikina Ponder & Waterhouse, 1997.Bullastra Bergh, 1901Lantzia Jousseaume, 1872Limnobulla Kruglov & Starobogatov, 1985Myxas G. B. Sowerby, 1822Orientogalba Kruglov & Starobogatov, 1985Pacifimyxas Kruglov & Starobogatov, 1985Pectinidens Pilsbry, 1911Radix Montfort, 1810 - type genus of the subfamily Radicinae
  • * subgenus Radix sensu stricto
  • * subgenus Peregriana Servain, 1881Cerasina Kobelt, 1880 - taxon inquirendum: maybe it is a synonym of Radix
;Genera brought into synonymy:Amphipeplea Nilsson, 1822: synonym of Myxas G. B. Sowerby I, 1822Auriculariana Servain, 1881: synonym of Radix Montfort, 1810Cyclolimnaea Dall, 1905: synonym of Myxas G. B. Sowerby I, 1822Gulnaria Turton, 1831: synonym of Radix Montfort, 1810Kutikina Ponder & Waterhouse, 1997: synonym of Austropeplea Cotton, 1942Neritostoma H. Adams & A. Adams, 1855: synonym of Radix Montfort, 1810
subfamily LancinaeIdaholanx Clark, Campbell & Lydeard, 2017 - with the only species Idaholanx fresti Clark, Campbell & Lydeard, 2017Lanx Clessin, 1880 - type genus of the subfamily Lancinae
† subfamily ScalaxinaeScalaxis Pilsbry, 1909 - type genus of the subfamily Scalaxinae
† subfamily Valencieniinae
  • † Provalenciennesia Gorjanović-Kramberger, 1923
  • † Valenciennius Rousseau, 1842 - type genus of the subfamily Valencieniinae
;Genera brought into synonymy:
  • † Provalenciennius Gorjanović-Kramberger, 1923: synonym of † Provalenciennesia Gorjanović-Kramberger, 1923
  • † Valenciennesia Fischer, 1859: synonym of † Valenciennius Rousseau, 1842
subfamily ?Adelinella Wenz, 1922
  • † Boskovicia Brusina, 1894
  • † Clivunella Katzer, 1918
  • † Corymbina Bulowski, 1892Fisherola Hannibal, 1912Glacilimnea Iredale, 1943
  • † Hiscerus Gorjanović-Kramberger, 1923Peplimnea Iredale, 1943Simlimnea Iredale, 1943
  • † Undulotheca Gorjanović-Kramberger, 1923
  • † Velutinopsis Sandberger, 1875
  • † Zagrabica Brusina, 1884

Distribution

Lymnaeidae snails occur worldwide, however, most species occur in the Palearctic and Nearctic regions. An unidentified fragmentary lymnaeid from deposits of the Meyer Desert Formation was the first freshwater snail recorded from Antarctica.

Description

This family exhibits a great diversity in shell morphology but extremely homogeneous anatomical traits. Diversity of shell morphology is linked to substantial eco-phenotypic plasticity. Hubendick illustrated this point by compiling up to 1143 species names, a large number of which he synonymized. In contrast, the anatomy of their reproductive tracts is extremely homogeneous. Immunological, cytogenetical, enzyme electrophoresis studies, and DNA-based approaches have demonstrated extensive homoplasy in anatomical characters.

Ecology

Lymnaeidae are of major medical and veterinary importance since they act as vectors of parasites that severely affect human populations and livestock, and cause important economic losses. Lymnaeids serve as intermediate hosts of at least 71 trematode species distributed among 13 families, including some species of Schistosomatidae and Echinostomatidae, with implications for human health, and Paramphistomum daubneyi, which is of veterinary interest. The most emblematic case of parasite transmitted by lymnaeids is Fasciola hepatica, the agent of fascioliasis. Mollusks, generally lymnaeids, are required as intermediate hosts to complete the life cycle of Fasciola hepatica. At least 20 species of Lymnaeidae have been described as potential vectors of fascioliasis.