Freshwater snails can be found throughout the world in habitats ranging
from ephemeral pools to the largest lakes, and from small seeps and springs
to major rivers. The majority of freshwater gastropods have a shell, with
very few exceptions. Some groups of snails that live in freshwater respire
using gills, whereas other groups need to reach the surface to breathe air.
Most feed on algae, but many are detritivors and some are filter feeders.
According to present classification efforts, there are about 4,000 species
of freshwater gastropods. At least 33–38 independent lineages of
gastropods have successfully colonized freshwater environments. It is not
possible to quantify the exact number of these lineages yet, because they have
yet to be clarified within the Cerithioidea. From six to eight of these
independent lineages occur in North America.What it eats is pretty much
algae and whatever is left by fish but sometimes they eat food that people
leave in water. Taxonomy
= 2005 taxonomy= The following cladogram is an overview
of the main clades of gastropods based on the taxonomy of Bouchet & Rocroi,
with families that contain freshwater species marked in boldface:
= 2010 taxonomy= The following cladogram is an overview
of the main clades of gastropods based on the taxonomy of Bouchet & Rocroi,
modified after Jörger et al. and simplified with families that contain
freshwater species marked in boldface: are not depicted within Panpulmonata for
simplification. Some of these highlighted families consist entirely of
freshwater species, but some of them also contain, or even mainly consist of,
marine species.) Neritimorpha
Primitive "Prosobranch" gilled snails with a shelly operculum.
Neritiliidae, 5 extant freshwater species
Neritidae, largely confined to the tropics, also the rivers of Europe,
family includes the marine "nerites". There are about 110 extant freshwater
species. Caenogastropoda
A large group of gilled operculate snails, largely marine. In freshwater
habitats there are ten major families, as well as other families of lesser
importance: Architaenioglossa
Ampullariidae, an exclusively freshwater family that is largely tropical and
includes the large "apple snails" kept in aquaria. 105-170 species.
Viviparidae, medium to large snails, live-bearing, commonly referred to as
"mystery snails". Worldwide except South America, and everywhere confined to
fresh waters. 125-150 species. Sorbeoconcha
Melanopsidae, family native to rivers draining to the Mediterranean, also
Middle East, and some South Pacific islands. About 25-50 species.
Pachychilidae - 165-225 species. native to South and Central America. Formerly
included with the Pleuroceridae by many authors.
Paludomidae - about 100 species in south Asia, diverse in African Lakes, and Sri
Lanka. Formerly classified with the Pleuroceridae by some authors.
Pleuroceridae, abundant and diverse in eastern North America, largely
high-spired snails of small to large size. About 150 species.
Semisulcospiridae, - primarily eastern Asia, Japan, also the Juga snails of
northwestern North America. Formerly included with the Pleuroceridae. About
50 species. Thiaridae, high-spired parthenogenic
snails of the tropics, includes those referred to as "trumpet snails" in
aquaria. About 110 species. Littorinimorpha
Littorinidae - 2 species in the genus Cremnoconchus are freshwater living in
waterfalls. Other species are marine. Amnicolidae - about 200 species.
Assimineidae - about 20 freshwater species, other are marine
Bithyniidae, small snails, native to Eastern Hemisphere. About 130 species.
Cochliopidae - 246 species. Helicostoidae, the only species
Helicostoa sinensis lives in China. Hydrobiidae, small to very small snails
found worldwide. About 1250 freshwater species other are marine.
Lithoglyphidae - about 100 species. Moitessieriidae - 55 species.
Pomatiopsidae, small amphibious snails scattered worldwide, most diverse in
eastern and Southeast Asia. About 170 species.
Stenothyridae - about 60 freshwater species, others are marine.
Neogastropoda Buccinidae - 8-10 freshwater species in
the genus Clea, native to Southeast Asia. Other Buccinidae are marine.
Marginellidae - 2 freshwater species in the genus Rivomarginella, native to
Southeast Asia. Other Marginellidae are marine.
Heterobranchia Lower Heterobranchia
Glacidorbidae - 20 species. Valvatidae, small low-spired snails
referred to as "valve snails". 71 species.
Acochlidiacea Acochlidiidae - 5 shell-less species:
Acochlidium amboinense, Acochlidium bayerfehlmanni, Acochlidium fijiiensis,
Palliohedyle sutteri and Strubellia paradoxa
Tantulidae - there is only one species which is shell-less Tantulum elegans.
Pulmonata, Basommatophora Basommatophorans are pulmonate or
air-breathing aquatic snails, characterized by having their eyes
located at the base of their tentacles, rather than at the tips, as in the true
land snails Stylommatophora. The majority of basommatophorans have shells
that are thin, translucent, and relatively colorless, and all five
freshwater basommatophoran families lack an operculum.
Chilinidae, small to medium-sized snails confined to temperate and cold South
America. About 15 species. Latiidae, small limpet-like snails
confined to New Zealand. One or three species.
Acroloxidae - about 40 species. Lymnaeidae, found worldwide, but are
most numerous in temperate and northern regions. These are the dextral pond
snails. About 100 species. Planorbidae, "rams horn" snails, with a
worldwide distribution. About 250 species.
Physidae, left-handed "pouch snails", native to Europe, Asia, North America.
About 80 species. As human food
Several different freshwater snail species are eaten in Asian cuisine.
Archaeological investigations in Guatemala have revealed that the diet of
the Maya of the Classic Period included freshwater snails.
Aquarium snails In the developed world, people encounter
freshwater snails most commonly in aquaria along with tropical fish.
Species available vary in different parts of the world. In the United
States, commonly available species include ramshorn snails such as
Planorbella duryi, apple snails such as Pomacea bridgesii, the high-spired
thiarid malaysian trumpet snail Melanoides tuberculata, and several
Neritina species. Parasitology
Freshwater snails are widely known to be hosts in the lifecycles of a variety of
human and animal parasites, particularly trematodes or "flukes". Some of these
relations for prosobranch snails include Oncomelania in the family Pomatiopsidae
as hosts of Schistosoma, and Bithynia, Parafossarulus and Amnicola as hosts of
Opisthorchis. Thiara and Semisulcospira may host Paragonimus. Juga plicifera may
host Nanophyetus salmincola. Basommatophoran snails are even more
widely infected, with many Biomphalaria serving as hosts for Schistosoma
mansoni, Fasciolopsis and other parasitic groups. The tiny Bulinus
snails are hosts for Schistosoma haematobium. Lymnaeid snails serve as
hosts for Fasciola and the cerceriae causing swimmer's itch. The term
“neglected tropical diseases” applies to all snail-borne infections, including
schistosomiasis, fascioliasis, fasciolopsiasis, paragonimiasis,
opisthorchiasis, clonorchiasis, and angiostrongyliasis.
See also Land snail
Sea slug Sea snail
Slug References
This article incorporates CC-BY-2.5 text from the reference
Further reading Haynes A.. "The distribution of
freshwater gastropods on four Vanuatu islands: Espiritu Santo, Pentecost,
Éfate and Tanna". Annales de Limnologie 36(2): 101-111. doi:10.10512000006, PDF.
Vermeij J. & Wesselingh F. P.. "Neogastropod molluscs from the Miocene
of western Amazonia, with comments on marine to freshwater transitions in
molluscs". Journal of Paleontology 76(2): 265-270.
doi:10.1666/0022-3360(2002)0762.0.CO;2.