Lymnaeidae
Encyclopedia
Lymnaeidae is a taxonomic family
of small to large air-breathing freshwater snail
s, aquatic
pulmonate gastropod mollusks, that belong to the clade
Hygrophila
.
Lymnaeidae is the only family within the superfamily Lymnaeoidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005
).
, internal transcribed spacer
s ITS1 and ITS2 genes) 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 (America, Eurasia and the Indo-Pacific region). 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 spacer
s ITS1 and ITS2 genes showing phylogenic relations of Lymnaeidae by Correa et al. (2010):
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 (1968), two by Hubendick (1951), and up to 34 genera by others [13,59-62]. Results by Correa et al. (2010) indicate that genera in Lymnaeidae do not reflect phylogenetic relationships, to the notable exception of Radix (including Radix natalensis
).
The type species of Lymnaea is Lymnaea stagnalis
Linnaeus, 1758; the type species of Stagnicola
Jeffreys, 1830 is Stagnicola palustris
(= Lymnaea 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 (C2) and that Lymnaea is not a monophyletic group. Correa et al. (2010) proposed that species of clade C2 should all be called Lymnaea, according to the principle of priority
of the International Code of Zoological Nomenclature
(ICZN). By extension, Stagnicola should not be used to name species in clade C1a since the type species belongs to clade C2. Meier-Brook & Bargues (2002) 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. (2010) 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 and Waterhouse, 1997 (one species: Kutikina hispida) seems unjustified on the basis of the current phylogeny. This would also be consistent with results of Puslednik et al. (2009). It would be preferable to use Bullastra Pfeiffer, 1839 for all species of clade C3a to fit the ICZN.
subfamily Lymnaeinae
subfamily Lancinae
† subfamily Scalaxinae
† subfamily Valencieniinae
subfamily ?
and Nearctic
regions. An unidentified fragmentary lymnaeid from deposits of the Meyer Desert
Formation reported in 2003 has been the first freshwater snail
recorded from Antarctica.
morphology but extremely homogeneous anatomical traits. Diversity of shell morphology is linked to substantial eco-phenotypic plasticity
. Hubendick (1951) 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
(including prostate, penis and preputium) is extremely homogeneous. Immunological, cytogenetical
, enzyme electrophoresis
studies, and DNA-based approaches have demonstrated extensive homoplasy in anatomical characters.
liver flukes) 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
(Digenea: Fasciolidae), 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.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of small to large air-breathing freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....
s, aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
pulmonate gastropod mollusks, that belong to the clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
Hygrophila
Hygrophila (clade)
Hygrophila is a taxonomic clade of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks within the clade Panpulmonata.The families in this clade are basically air-breathing freshwater snails including freshwater limpets...
.
Lymnaeidae is the only family within the superfamily Lymnaeoidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005
Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
The taxonomy of the Gastropoda as it was revised by Philippe Bouchet and Jean-Pierre Rocroi is currently the most up-to-date overall system for classifying gastropod mollusks...
).
Subfamilies
This family consists of four subfamilies:- 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
Cladogram
Correa et al. (2010) examined phylogenetic relationships among 50 taxa of this family using a supermatrix approach (concatenation of the 16S16S ribosomal RNA
16S ribosomal RNA is a component of the 30S subunit of prokaryotic ribosomes. It is approximately 1.5kb in length...
, internal transcribed spacer
Internal transcribed spacer
ITS refers to a piece of non-functional RNA situated between structural ribosomal RNAs on a common precursor transcript. Read from 5' to 3', this polycistronic rRNA precursor transcript contains the 5' external transcribed sequence , 18S rRNA, ITS1, 5.8S rRNA, ITS2, 28S rRNA and finally the 3'ETS...
s ITS1 and ITS2 genes) involving both maximum likelihood
Maximum likelihood
In statistics, maximum-likelihood estimation is a method of estimating the parameters of a statistical model. When applied to a data set and given a statistical model, maximum-likelihood estimation provides estimates for the model's parameters....
and Bayesian inference
Bayesian inference
In statistics, Bayesian inference is a method of statistical inference. It is often used in science and engineering to determine model parameters, make predictions about unknown variables, and to perform model selection...
. Her phylogenetic analysis demonstrates the existence of three deep clades of Lymnaeidae representing the main geographic origin of species (America, Eurasia and the Indo-Pacific region). It demonstrates that the nomenclature of most genera in the Lymnaeidae does not reflect evolutionary relationships.
A cladogram based on sequences of 16S
16S ribosomal RNA
16S ribosomal RNA is a component of the 30S subunit of prokaryotic ribosomes. It is approximately 1.5kb in length...
, internal transcribed spacer
Internal transcribed spacer
ITS refers to a piece of non-functional RNA situated between structural ribosomal RNAs on a common precursor transcript. Read from 5' to 3', this polycistronic rRNA precursor transcript contains the 5' external transcribed sequence , 18S rRNA, ITS1, 5.8S rRNA, ITS2, 28S rRNA and finally the 3'ETS...
s ITS1 and ITS2 genes showing phylogenic relations of Lymnaeidae by Correa et al. (2010):
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 (1968), two by Hubendick (1951), and up to 34 genera by others [13,59-62]. Results by Correa et al. (2010) indicate that genera in Lymnaeidae do not reflect phylogenetic relationships, to the notable exception of Radix (including Radix natalensis
Radix natalensis
Radix natalensis is a species of freshwater snail, an aquatic gastropod mollusc in the family Lymnaeidae.It is widely distributed in Africa. It is a major intermediate host for Fasciola gigantica in Africa. Placement of this species in the genus Radix was confirmed by Correa et al...
).
The type species of Lymnaea is Lymnaea stagnalis
Lymnaea stagnalis
Lymnaea stagnalis, better known as the great pond snail, is a species of large air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae.-Distribution:The distribution of this species is Holarctic...
Linnaeus, 1758; the type species of Stagnicola
Stagnicola
Stagnicola is a genus of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails.-Species:The genus includes the following species:* Stagnicola arctica...
Jeffreys, 1830 is Stagnicola palustris
Stagnicola palustris
Stagnicola palustris is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.-Description:...
(= Lymnaea palustris); and the type species of Omphiscola
Omphiscola
Omphiscola is a genus of small to medium-sized, air-breathing, freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae.-Species:Species within the genus include:* Omphiscola glabra - type species...
Rafinesque, 1819 is Omphiscola glabra
Omphiscola glabra
Omphiscola glabra is a species of small to medium-size, air-breathing, freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae.-Distribution:This European snail can be found from southern Scandinavia to southern Spain....
. However, it is clear that these three species belong to the same clade (C2) and that Lymnaea is not a monophyletic group. Correa et al. (2010) proposed that species of clade C2 should all be called Lymnaea, according to the principle of priority
Principle of Priority
thumb|270px|Boa manditraIn zoology, the scientific study of animals, the Principle of Priority is one of the guiding principles of the International Code of Zoological Nomenclature, defined by Article 23....
of the International Code of Zoological Nomenclature
International Code of Zoological Nomenclature
The International Code of Zoological Nomenclature is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals...
(ICZN). By extension, Stagnicola should not be used to name species in clade C1a since the type species belongs to clade C2. Meier-Brook & Bargues (2002) suggested including Stagnicola emarginata, Stagnicola elodes
Stagnicola elodes
Stagnicola elodes is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.- Further reading :...
, Stagnicola catascopium and Lymnaea occulta within a new genus Catascopia
Catascopia
Catascopia is a genus of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails.- Species :The genus Catascopia includes:...
, while Stagnicla caperata would belong to the genus Hinkleyia Baker, 1928. The phylogeny by Correa et al. (2010) 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
Galba
Galba , was Roman Emperor for seven months from 68 to 69. Galba was the governor of Hispania Tarraconensis, and made a bid for the throne during the rebellion of Julius Vindex...
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 and Waterhouse, 1997 (one species: Kutikina hispida) seems unjustified on the basis of the current phylogeny. This would also be consistent with results of Puslednik et al. (2009). 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 Lymnaeinae
- Acella Haldeman, 1841
- CatascopiaCatascopiaCatascopia is a genus of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails.- Species :The genus Catascopia includes:...
Meier-Brook & Bargues, 2002 - Galba Schrank, 1803
- LymnaeaLymnaeaLymnaea is a genus of small to large-sized air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails.Lymnaea is the type genus of the family Lymnaeidae.-Species:...
Lamarck, 1799 - type genus of the family Lymnaeidae - MyxasMyxasMyxas is a genus of small air-breathing freshwater snails, aquatic gastropod mollusks in the family Lymnaeidae, the pond snails.-Species:Species within this genus include:* Myxas glutinosa - type species...
G. B. Sowerby, 1822 - OmphiscolaOmphiscolaOmphiscola is a genus of small to medium-sized, air-breathing, freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae.-Species:Species within the genus include:* Omphiscola glabra - type species...
Rafinesque, 1819 - PseudosuccineaPseudosuccineaPseudosuccinea is a genus of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails....
F. C. Baker, 1908 - Radix Montfort, 1810
- StagnicolaStagnicolaStagnicola is a genus of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails.-Species:The genus includes the following species:* Stagnicola arctica...
Jeffreys, 1820
subfamily Lancinae
- LantziaLantziaLantzia is a genus of small to large-sized air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails....
Jousseaume, 1872 - Lanx Clessin, 1880 - type genus of the subfamily Lancinae
† subfamily Scalaxinae
- Scalaxis Pilsbry, 1909 - type genus of the subfamily Scalaxinae
† subfamily Valencieniinae
- Valenciennius Rousseau, 1842 - type genus of the subfamily Valencieniinae
subfamily ?
- Adelinella Wenz, 1922
- AustropepleaAustropepleaAustropeplea is a genus of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails.- Species :Species within the genus Austropeplea include:* Autropeplea lessoni* Austropeplea ollula...
B. C. Cotton, 1942 - Bakerilymnaea Weyrauch, 1964
- Boskovicia Brusina, 1894
- Bullastra Bergh, 1901
- Bulimnea Haldeman, 1841
- Corymbina Bulowski, 1892
- ErinnaErinna (gastropod)Erinna is a genus of air-breathing, freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails. This genus is endemic to the Hawaiian Islands, United States.- Species :Species within the genus Erinna include:...
H. & A. Adams, 1858 - Fisherola Hannibal, 1912
- Fossaria Westerlund, 1885
- Kutikina Ponder & Waterhouse, 1997 - one species: Kutikina hispida
- Pseudisidora Thiele, 1931
- Velutinopsis Sandberger, 1875
- Zagrabia Brusina, 184?
Distribution
Lymnaeidae snails are distributed worldwide. Most of its species occur in the PalearcticPalearctic
The Palearctic or Palaearctic is one of the eight ecozones dividing the Earth's surface.Physically, the Palearctic is the largest ecozone...
and Nearctic
Nearctic
The Nearctic is one of the eight terrestrial ecozones dividing the Earth's land surface.The Nearctic ecozone covers most of North America, including Greenland and the highlands of Mexico...
regions. An unidentified fragmentary lymnaeid from deposits of the Meyer Desert
Meyer Desert
Meyer Desert is a triangular ice-free area of about at the north end of the Dominion Range, near the confluence of the Beardmore and Mill Glaciers...
Formation reported in 2003 has been the first freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....
recorded from Antarctica.
Description
This family exhibits a great diversity in shellGastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
morphology but extremely homogeneous anatomical traits. Diversity of shell morphology is linked to substantial eco-phenotypic plasticity
Phenotypic plasticity
Phenotypic plasticity is the ability of an organism to change its phenotype in response to changes in the environment. Such plasticity in some cases expresses as several highly morphologically distinct results; in other cases, a continuous norm of reaction describes the functional interrelationship...
. Hubendick (1951) 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
Reproductive system of gastropods
The reproductive system of gastropods varies greatly from one group to another within this very large and diverse taxonomic class of animals...
(including prostate, penis and preputium) is extremely homogeneous. Immunological, cytogenetical
Cytogenetics
Cytogenetics is a branch of genetics that is concerned with the study of the structure and function of the cell, especially the chromosomes. It includes routine analysis of G-Banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ...
, enzyme electrophoresis
Electrophoresis
Electrophoresis, also called cataphoresis, is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field. This electrokinetic phenomenon was observed for the first time in 1807 by Reuss , who noticed that the application of a constant electric...
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 (helminths, mainly trematodes, e.g., FasciolaFasciola
Fasciola is a genus of trematodes which includes economically important parasite species. Members of genus Fasciola belongs to liver flukes. They causes the disease fasciolosis.- Species :*Fasciola hepatica*Fasciola gigantica...
liver flukes) 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
Schistosomatidae
Schistosomatidae is a family of digenetic trematodes with complex parasitic life cycles. Immature developmental stages of schistosomes are found in molluscs and adults occur in vertebrates. The best studied group, the blood flukes of the genus Schistosoma, infect and cause disease in humans...
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
Fasciola hepatica
Fasciola hepatica, also known as the common liver fluke or sheep liver fluke, is a parasitic flatworm of the class Trematoda, phylum Platyhelminthes that infects the livers of various mammals, including humans. The disease caused by the fluke is called fascioliasis . F...
(Digenea: Fasciolidae), the agent of fascioliasis
Fascioliasis
Fasciolosis also known as Fascioliasis, Fasciolasis, distomatosis and liver rot, is an important helminth disease caused by two trematodes Fasciola hepatica and Fasciola gigantica. This disease belongs to the plant-borne trematode zoonoses. In Europe, the Americas and Oceania only F...
. 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.
Further reading
- Kruglov N. D. & Starobogatov Y. I. (1993). "Annotated and illustrated catalogue of species of the family Lymnaeidae (Gastropoda, Pulmonata, Lymnaeiformes) of Palaearctic and adjacent river drainage areas. Part 1." Ruthenica 1: 65–92.