Biomphalaria Temporal range: | |
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An albino individual of Biomphalaria glabrata | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Superorder: | Hygrophila |
Family: | Planorbidae |
Subfamily: | Planorbinae |
Tribe: | Helisomatini |
Genus: | Biomphalaria Preston, 1910 [1] |
Type species | |
Biomphalaria smithi Preston, 1910 | |
Diversity [2] | |
34 species | |
Synonyms | |
Taphius ( H. Adams & A. Adams, 1855) Planorbis (Planorbina) (Haldeman, 1842) Contents |
Biomphalaria is a genus of air-breathing freshwater snails, aquatic pulmonates belonging to the family Planorbidae, the ram's horn snails and their allies. [3] [4]
Biomphalaria is the type genus of the tribe Biomphalariini. Both Planorbis and Taphius are synonyms for Biomphalaria. [3] [5]
The shell of this species, like all planorbids is left coiling (sinistral), but is carried upside down and thus appears to be right coiling (dextral).
There are a suspected 35 [6] extant species in the genus Biomphalaria in total (21 American species and 14 Old World species). However, there are a large number of invalid taxa within the Biomphalaria literature, which is likely the result of several (if not all) species of Biomphalaria being subject to various sources of intraspecific variation such as ecophenotypic variation and indeterminate shell growth. [7] This intraspecific variation can make two individuals of the same species appear as two taxonomically distinct entities when identified using only morphological identification methods. [8] [9]
New World (South American) species include:
Old World (Africa, Madagascar and the Middle East) species include:
Confirmed species using molecular identification methods: [15] [16]
There is one known hybrid Biomphalaria glabrata × Biomphalaria alexandrina from Egypt. [17]
Suspected species identified using morphological methods:
A cladogram created from mitochondrial and nuclear DNA showing the phylogenic relationships of both New World (16) and Old World (7) species: [15]
Biomphalaria |
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The topology was consistent with the proposed Neotropical origins of the genus, with the oldest Biomphalaria fossils being dated from approximately 60 million years ago. [7] However, further analysis of the African Biomphalaria species found only B. camerunensis and B. pfeifferi were the only definitive African species, with the remain species being a part of (or a sister taxa to) the "Nilotic species complex": [16]
All of the African Biomphalaria species have low levels of genetic diversity, [19] [20] which is likely the result of their relatively recent evolutionary history.
The origin of the genus Biomphalaria is American. [15] The ancestor of Biomphalaria glabrata colonized Africa 2.3–4.5 [15] or 2-5 [21] millions years ago and speciated into all the African Biomphalaria species. [15]
Natural populations of these snails are usually found in tropical standing water or freshwater in South America and Africa, but they also reach 30° latitude in subtropical areas. Many species of these red-blooded planorbid snails (Gastropoda: Basommatophora) are able to survive a long time when removed from their freshwater habitat. Of the 34 Biomphalaria species, 4 ( Biomphalaria glabrata , Biomphalaria pfeifferi , Biomphalaria straminea , and Biomphalaria tenagophila ) have recently expanded their native ranges. They have been introduced to areas where other Biomphalaria species are endemic (e.g., Congo and Egypt) or to subtropical zones that have no frost period (Texas, Louisiana, Florida, Hong Kong). [6]
All species in the genus Biomphalaria except of native Biomphalaria obstructa has not yet become established in the US, but they are considered to represent a potentially serious threat as a pest, an invasive species which could negatively affect agriculture, natural ecosystems, human health or commerce. Therefore, it has been suggested that this species be given top national quarantine significance in the USA. [22]
This genus of snails is medically important, because the snails can carry a parasite of humans which represents a serious disease risk: the snails serve as an intermediate host (vector) for the human parasitic blood fluke, Schistosoma mansoni , that infects about 83 million people. [23]
The human disease schistosomiasis (aka snail fever) caused by all Schistosoma species (transmitted also by other snails) infects 200 million people. [24] The fluke, which is found primarily in tropical areas, infects mammals (including humans) via contact with water that contains schistosome larvae (cercariae) which have previously been released from the snail. Infection occurs via penetration of cercariae through the skin. [25]
Eighteen species of Biomphalaria are intermediate hosts for Schistosoma mansoni; seven species of the genus have not been tested for this susceptibility and nine species are resistant. [26] Altogether about 30 species of parasites from Africa and at least 20 species from the Neotropics are known to parasitize Biomphalaria. [26]
Schistosoma is a genus of trematodes, commonly known as blood flukes. They are parasitic flatworms responsible for a highly significant group of infections in humans termed schistosomiasis, which is considered by the World Health Organization to be the second-most socioeconomically devastating parasitic disease, with hundreds of millions infected worldwide.
Schistosoma mansoni is a water-borne parasite of humans, and belongs to the group of blood flukes (Schistosoma). The adult lives in the blood vessels near the human intestine. It causes intestinal schistosomiasis. Clinical symptoms are caused by the eggs. As the leading cause of schistosomiasis in the world, it is the most prevalent parasite in humans. It is classified as a neglected tropical disease. As of 2021, the World Health Organization reports that 251.4 million people have schistosomiasis and most of it is due to S. mansoni. It is found in Africa, the Middle East, the Caribbean, Brazil, Venezuela and Suriname.
Planorbidae, common name the ramshorn snails or ram's horn snails, is a family of air-breathing freshwater snails, aquatic pulmonate gastropod molluscs. Unlike most molluscs, the blood of ram's horn snails contains iron-based hemoglobin instead of copper-based hemocyanin. As a result, planorbids are able to breathe oxygen more efficiently than other molluscs. The presence of hemoglobin gives the body a reddish colour. This is especially apparent in albino animals.
Capsaspora is a monotypic genus containing the single species Capsaspora owczarzaki. C. owczarzaki is a single-celled eukaryote that occupies a key phylogenetic position in our understanding of the origin of animal multicellularity, as one of the closest unicellular relatives to animals. It is, together with Ministeria vibrans, a member of the Filasterea clade. This amoeboid protist has been pivotal to unraveling the nature of the unicellular ancestor of animals, which has been proved to be much more complex than previously thought.
Biomphalaria glabrata is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Biomphalaria tenagophila is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Biomphalaria smithi is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Biomphalaria alexandrina is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails and their allies.
Biomphalaria straminea is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Biomphalaria pfeifferi is a species of air-breathing freshwater snail, an aquatic animal pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Biomphalaria andecola is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Biomphalaria peregrina is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Biomphalaria stanleyi is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Biomphalaria havanensis, common name the ghost rams-horn, is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Biomphalaria sudanica is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod belonging to the family Planorbidae, the ram's horn snails. Biomphalaria sudanica has a discoidal, brown shell with an approximate shell diameter of 9–11mm. Biomphalaria sudanica is a medically important pest, due to it being an intermediate host of the intravascular trematode genus, Schistosoma.
Biomphalaria kuhniana is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Indoplanorbis is a genus of air-breathing freshwater snail. Its only member species is Indoplanorbis exustus, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails. The species is widely distributed across the tropics. It serves as an important intermediate host for several trematode parasites. The invasive nature and ecological tolerance of Indoplanorbis exustus add to its importance in veterinary and medical science.
Schistosoma spindale is a species of digenetic trematode in the family Schistosomatidae. It causes intestinal schistosomiasis in the ruminants.
FMRFamide, a neuropeptide involved in cardiac activity regulation, is found in Biomphalaria glabrata, a species of a freshwater snail best known for its role as the intermediate host for the human-infecting trematode parasite Schistosoma mansoni.
Biomphalaria choanomphala is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod in the family Planorbidae, the ram's horn snails. Biomphalaria choanomphala has a discoidal, brownish-yellow shell with an approximate shell diameter of 6–10 mm. Biomphalaria choanomphala is a medically important pest, due to it being an intermediate host of the intravascular trematode genus, Schistosoma.
This article incorporates public domain text from the Majoros et al. reference. [2]
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