Oncomelania Minima Map Japan
   HOME

TheInfoList



OR:

''Oncomelania'' is a
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of very small
tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...
freshwater snail Freshwater snails are gastropod mollusks that live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs t ...
s,
aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...
gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...
mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000  extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...
s in the
family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Pomatiopsidae Pomatiopsidae is a family of small, mainly freshwater snails, (some also occur in other habitats) that have gills and an operculum, aquatic gastropod mollusks in the superfamily Truncatelloidea (according to the taxonomy of the Gastropoda b ...
. These ''Oncomelania'' snails are distantly related to the marine periwinkle, and more closely related to the small marine snails of the family
Rissoidae Rissoidae is a large family of sea snails. Members of the Rissoidae are very small in size and possess an operculum. Distribution and habitat Rissoidae are found worldwide. They live on sandy or gravel bottoms among algae or marine plants. Th ...
.


Species

There are twoKameda Y. & Kato M. (2011). "Terrestrial invasion of pomatiopsid gastropods in the heavy-snow region of the Japanese Archipelago". ''
BMC Evolutionary Biology ''BMC Ecology and Evolution'' (since January 2021), previously ''BMC Evolutionary Biology'' (2001–2020), is a peer-reviewed open access scientific journal covering all fields of evolutionary biology, including phylogenetics and palaeontology ...
'' 11: 118. .
species in the genus ''Oncomelania'': * ''
Oncomelania hupensis ''Oncomelania hupensis'' is a species of very small tropical freshwater snail, an aquatic animal, aquatic gastropod mollusk in the family Pomatiopsidae. Distribution ''Oncomelania hupensis'' has been found in List of non-marine molluscs of Chi ...
'' Gredler, 1881 - type species, this polytypic species has a number of subspecies * '' Oncomelania minima'' P. Bartsch, 1936 Woodruff et al. (1999) recognized also the following species: * '' Oncomelania lindoensis'' Davis & Carney, 1973 - from Lake Lindu (
Lore Lindu National Park Lore Lindu National Park is a protected area of forest on the Indonesian island of Sulawesi, in the province of Central Sulawesi. The List of national parks of Indonesia, Indonesian national park is 2,180 km2 covering both lowland and mont ...
),
Sulawesi Sulawesi ( ), also known as Celebes ( ), is an island in Indonesia. One of the four Greater Sunda Islands, and the List of islands by area, world's 11th-largest island, it is situated east of Borneo, west of the Maluku Islands, and south of Min ...
Japanese Red List Data Book (2006) recognizes also the following additional species: * '' Oncomelania shini'' - as
Vulnerable species A vulnerable species is a species which has been Conservation status, categorized by the International Union for Conservation of Nature as being threatened species, threatened with extinction unless the circumstances that are threatened species, ...
in Japan * '' Oncomelania sakuyamai'' - with no conservation status evaluated in Japan


Distribution

This genus has not yet become established in the USA, but it is considered to represent a potentially serious threat as a pest, an
invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...
which could negatively affect agriculture, natural ecosystems, human health or commerce. Therefore, it has been suggested that this species be given top national
quarantine A quarantine is a restriction on the movement of people, animals, and goods which is intended to prevent the spread of disease or pests. It is often used in connection to disease and illness, preventing the movement of those who may have bee ...
significance in the USA.


Evolution

About the origin and evolution history of ''Oncomelania'', Davis (1979)Davis G. M. (1979). "The origin and evolution of the gastropod family Pomatiopsidae, with emphasis on the Mekong river Triculinae". ''
Academy of natural Sciences of Philadelphia The Academy of Natural Sciences of Drexel University, formerly the Academy of Natural Sciences of Philadelphia, is the oldest natural science research institution and museum in the Americas. It was founded in 1812, by many of the leading natur ...
'', Monograph 20: 1-120.
at Google Books
proposed a
Gondwana Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...
n origin for the
Pomatiopsidae Pomatiopsidae is a family of small, mainly freshwater snails, (some also occur in other habitats) that have gills and an operculum, aquatic gastropod mollusks in the superfamily Truncatelloidea (according to the taxonomy of the Gastropoda b ...
, with rafting to mainland Asia via the
Indian Craton The geology of India is diverse. Different regions of the Indian subcontinent contain rocks belonging to different geologic periods, dating as far back as the Eoarchean Era. Some of the rocks are very deformed and altered. Other deposi ...
after break-up of Gondwanan and colonization of South-East Asia and China. It is hypothesized that ''Oncomelania'' snails, arrived in southwestern China from Indian before the second (major)
Tibetan orogeny Tibetan may mean: * of, from, or related to Tibet * Tibetan people, an ethnic group * Tibetan language: ** Classical Tibetan, the classical language used also as a contemporary written standard ** Standard Tibetan, the most widely used spoken diale ...
(2.5 Ma), then evolved and spread down their respective river systems, to mainland of China, Indonesia and Philippines. Although mutation rate calibrations using fossil data is impossible here, many studies have demonstrated the confidence that molecular data can provide reasonable estimates of divergence time. Data by Zhao et al. (2010) suggested that the two subspecies of ''
Oncomelania hupensis ''Oncomelania hupensis'' is a species of very small tropical freshwater snail, an aquatic animal, aquatic gastropod mollusk in the family Pomatiopsidae. Distribution ''Oncomelania hupensis'' has been found in List of non-marine molluscs of Chi ...
'' began to diverse as early about 2–6 Ma based on the invertebrate ITS substitution rate range. Zhao et al. (2010) did not find any strong molecular and fossil evidences about ''Oncomelania'' evolution, but the reported ''Oncomelania'' fossil found in
Guangxi Guangxi,; officially the Guangxi Zhuang Autonomous Region, is an Autonomous regions of China, autonomous region of the China, People's Republic of China, located in South China and bordering Vietnam (Hà Giang Province, Hà Giang, Cao Bằn ...
(1 Ma) by
Nils Hjalmar Odhner Nils Hjalmar Odhner (6 December 1884 – 12 June 1973) was a Swedish zoologist who studied mollusks, a malacologist. He was professor of invertebrate zoology at the Swedish Museum of Natural History, Stockholm, and a member of the Royal Swedish Ac ...
in 1930 and geological movement make this diversification time reasonable. It provides a new insight into the ''Oncomelania'' evolution history although the substitution rate needs to be verified with new fossil and molecular data in future study.


Parasites

Various ''Oncomelania'' species are significant medically, because they can serve as vectors for two serious human diseases: they can carry the
schistosomiasis Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever is a neglected tropical helminthiasis, disease caused by parasitism, parasitic Schistosoma, flatworms called schistosomes. It affects both humans and animals. It affects ...
blood fluke
parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...
, and the paragonimus lung fluke parasites. The
miracidia The miracidium is the second stage in the life cycle of trematodes. When trematode eggs are laid and come into contact with fresh water, they hatch and release miracidium. In this phase, miracidia are ciliated and free-swimming. This stage is comp ...
reproduce asexually through sporocyst stages within these
intermediate host In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include ...
s, resulting in the production of many free-swimming
cercariae A cercaria (plural cercariae) is a larval form of the trematode class of parasites. It develops within the germinal cells of the sporocyst or redia. A cercaria has a tapering head with large penetration glands. It may or may not have a long swim ...
.Riley S, Carabin H, Bélisle P, Joseph L, Tallo V, et al. (2008). "Multi-Host Transmission Dynamics of ''Schistosoma japonicum'' in Samar Province, the Philippines". '' PLoS Medicine'' 5(1): e18. . Research conducted in the 1950s by Chinese
parasitologist Parasitology is the study of parasites, their hosts, and the relationship between them. As a biological discipline, the scope of parasitology is not determined by the organism or environment in question but by their way of life. This means it f ...
and
Harvard Harvard University is a private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher lear ...
graduate Chen Xintao from revealed infection rates as high as 31.1% in
Guangdong ) means "wide" or "vast", and has been associated with the region since the creation of Guang Prefecture in AD 226. The name "''Guang''" ultimately came from Guangxin ( zh, labels=no, first=t, t= , s=广信), an outpost established in Han dynasty ...
Province, China. In response, a government initiative focused on filling ditches and eliminating breeding grounds for Oncomelania snails led to significant improvements in controlling the schistosomiasis epidemic.


Human Consumption

''Oncomelania'' species are still commonly consumed throughout China.


References

This article incorporates CC-BY-2.0 text from the reference and CC-BY-2.5 text from the referenceZhao Q. P., Jiang M. S., Littlewood D. T. J. & Nie P. (2010). "Distinct Genetic Diversity of ''Oncomelania hupensis'', Intermediate Host of ''Schistosoma japonicum'' in Mainland China as Revealed by ITS Sequences". ''
PLoS Neglected Tropical Diseases ''PLOS Neglected Tropical Diseases'' is a peer-reviewed open access scientific journal devoted to the study of neglected tropical diseases, including helminth, bacterial, viral, protozoan, and fungal infections endemic to tropical regions. ''PLOS ...
'' 4(3): e611. .
{{Taxonbar, from=Q5225925 Pomatiopsidae