Biomphalaria choanomphala
{{Short description|Species of mollusc}}
{{Speciesbox
| image = Biomphalaria choanomphala.png
| image_caption = Apical and apertural view of Biomphalaria choanomphala.
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| taxon = Biomphalaria choanomphala
| authority = (E.von Martens, 1879)
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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,{{Cite journal |last1=Pointier |first1=J. P. |last2=David |first2=P. |last3=Jarne |first3=P. |year=2005 |title=Biological invasions: The case of planorbid snails |journal=Journal of Helminthology |volume=79 |issue=3 |pages=249–256 |doi=10.1079/JOH2005292 |pmid=16153319 |s2cid=11158571}} due to it being an intermediate host of the intravascular trematode genus, Schistosoma.{{cite journal |last1=Hofkin |first1=Bruce V. |last2=Koech |first2=Davy K. |last3=Oumaj |first3=John |last4=Loker |first4=Eric S. |date=October 1991 |title=The North American Crayfish Procambarus clarkii and the Biologica Control of Schistosome-Transmitting Snails in Kenya: Laboratory and Field Investigations |journal=Biological Control |volume=1 |issue=3 |pages=183–187 |doi=10.1016/1049-9644(91)90065-8|bibcode=1991BiolC...1..183H }}
Habitat and distribution
Biomphalaria choanomphala is an African species found in freshwater habitats such as rivers, streams, and ponds. Their head has a pair of tentacles with eyes at the base, and a siphon for breathing and waste elimination. It is known to prefer slow-moving water with vegetation, where it feeds on algae and detritus.
Distribution of Biomphalaria choanomphala include:
- East Africa: Lake Victoria (Kenya, Tanzanian and Uganda).{{Cite journal |last1=Standley |first1=Claire J |last2=Goodacre |first2=Sara L |last3=Wade |first3=Christopher M |last4=Stothard |first4=J Russell |date=December 2014 |title=The population genetic structure of Biomphalaria choanomphala in Lake Victoria, East Africa: implications for schistosomiasis transmission |journal=Parasites & Vectors |language=en |volume=7 |issue=1 |pages=524 |doi=10.1186/s13071-014-0524-4 |issn=1756-3305 |pmc=4254209 |pmid=25406437 |doi-access=free }}
Ecology and behavior
Biomphalaria choanomphala is known to be an intermediate host for the parasitic flatworms Schistosoma mansoni, which is responsible for causing intestinal schistosomiasis in humans. The snail's role as an intermediate host allows the parasite to complete its life cycle and infect humans who come into contact with contaminated water sources where it inhabits.
In addition to its role in transmitting parasites, Biomphalaria choanomphala also plays an important ecological role in its freshwater habitat. The snail feeds on algae and detritus, helping to regulate the nutrient balance of the ecosystem. It also serves as a food source for many predators, including fish, birds, and other invertebrates.
Conservation status and biological importance
Biomphalaria choanomphala is not considered a threatened species, and its population is stable in its native range. However, the species' role as an intermediate host for schistosomiasis makes it an important target for disease control programs. Constant efforts are underway to reduce the incidence of schistosomiasis by controlling the snail population through chemical treatments and biological control methods.
Phylogeny
Biomphalaria choanomphala is a part of the "Nilotic Species Complex" alongside B. alexandrina, B. angulosa, B. smithi, B. stanleyi and B. sudanica.{{Cite journal |last1=JØRGENSEN |first1=ASLAK |last2=KRISTENSEN |first2=THOMAS K. |last3=STOTHARD |first3=J. RUSSELL |date=October 2007 |title=Phylogeny and biogeography of African Biomphalaria (Gastropoda: Planorbidae), with emphasis on endemic species of the great East African lakes |journal=Zoological Journal of the Linnean Society |volume=151 |issue=2 |pages=337–349 |doi=10.1111/j.1096-3642.2007.00330.x |issn=1096-3642|doi-access=free }}
File:Biomphalaria Phylogenetic Tree.png
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Ecological phenotypes
Biomphalaria choanomphala has been the subject of multiple ecological and genetic studies, which have revealed its shell morphology can vary as a result of environmental factors.{{Cite journal |last1=Standley |first1=Claire J. |last2=Wade |first2=Chris |last3=Stothard |first3=J. Russell |date=2011-10-24 |title=A Fresh Insight into Transmission of Schistosomiasis: A Misleading Tale of Biomphalaria in Lake Victoria |journal=PLOS ONE |volume=6 |issue=10 |pages=e26563 |doi=10.1371/journal.pone.0026563 |pmid=22046308 |pmc=3200340 |bibcode=2011PLoSO...626563S |issn=1932-6203 |doi-access=free }}{{Cite journal |last1=Standley |first1=Claire J. |last2=Vounatsou |first2=Penelope |last3=Gosoniu |first3=Laura |last4=Jørgensen |first4=Aslak |last5=Adriko |first5=Moses |last6=Lwambo |first6=Nicholas J. S. |last7=Lange |first7=Charles N. |last8=Kabatereine |first8=Narcis B. |last9=Stothard |first9=J. Russell |date=2012-01-03 |title=The distribution of Biomphalaria (Gastropoda: Planorbidae) in Lake Victoria with ecological and spatial predictions using Bayesian modelling |url=http://dx.doi.org/10.1007/s10750-011-0962-3 |journal=Hydrobiologia |volume=683 |issue=1 |pages=249–264 |doi=10.1007/s10750-011-0962-3 |s2cid=254549615 |issn=0018-8158|url-access=subscription }} Several studies have shown that B. choanomphala snails found within Lake Victoria have very different conchological morphologies, but are very similar genetically, suggesting these snails are likely a single species expressing two ecophenotypes.{{Cite journal |last1=Standley |first1=Claire J |last2=Goodacre |first2=Sara L |last3=Wade |first3=Christopher M |last4=Stothard |first4=J Russell |date=2014-11-19 |title=The population genetic structure of Biomphalaria choanomphala in Lake Victoria, East Africa: implications for schistosomiasis transmission |journal=Parasites & Vectors |volume=7 |issue=1 |page=524 |doi=10.1186/s13071-014-0524-4 |pmid=25406437 |s2cid=255983772 |issn=1756-3305|pmc=4254209 |doi-access=free }}{{Cite journal |last1=Zhang |first1=Si-Ming |last2=Bu |first2=Lijing |last3=Laidemitt |first3=Martina R. |last4=Lu |first4=Lijun |last5=Mutuku |first5=Martin W. |last6=Mkoji |first6=Gerald M. |last7=Loker |first7=Eric S. |date=2018-05-09 |title=Complete mitochondrial and rDNA complex sequences of important vector species of Biomphalaria, obligatory hosts of the human-infecting blood fluke, Schistosoma mansoni |url=http://dx.doi.org/10.1038/s41598-018-25463-z |journal=Scientific Reports |volume=8 |issue=1 |page=7341 |doi=10.1038/s41598-018-25463-z |pmid=29743617 |pmc=5943310 |bibcode=2018NatSR...8.7341Z |issn=2045-2322}}
Previous conchological morphology studies of Biomphalaria snails have categorised their species based on whether they exhibited a “lacustrine” (found within a lake) or a “non-lacustrine” shell morphology (found elsewhere).{{Cite journal |last1=DeJong |first1=Randall J. |last2=Morgan |first2=Jess A. T. |last3=Paraense |first3=W. Lobato |last4=Pointier |first4=Jean-Pierre |last5=Amarista |first5=Manuel |last6=Ayeh-Kumi |first6=Patrick F. K. |last7=Babiker |first7=Ahmed |last8=Barbosa |first8=Constança S. |last9=Brémond |first9=Philippe |last10=Pedro Canese |first10=Andrés |last11=de Souza |first11=Cecilia Pereira |last12=Dominguez |first12=Claudio |last13=File |first13=Sharon |last14=Gutierrez |first14=Alfredo |last15=Incani |first15=R. Nino |date=2001-12-01 |title=Evolutionary Relationships and Biogeography of Biomphalaria (Gastropoda: Planorbidae) with Implications Regarding Its Role as Host of the Human Bloodfluke, Schistosoma mansoni |journal=Molecular Biology and Evolution |volume=18 |issue=12 |pages=2225–2239 |doi=10.1093/oxfordjournals.molbev.a003769 |pmid=11719572 |issn=1537-1719|doi-access=free }}{{Cite journal |last1=Plam |first1=Maria |last2=Jørgensen |first2=Aslak |last3=Kristensen |first3=Thomas K. |last4=Madsen |first4=Henry |date=April 2008 |title=SympatricBiomphalariaspecies (Gastropoda: Planorbidae) in Lake Albert, Uganda, show homoplasies in shell morphology |url=http://dx.doi.org/10.1080/15627020.2008.11407404 |journal=African Zoology |volume=43 |issue=1 |pages=34–44 |doi=10.1080/15627020.2008.11407404 |s2cid=84525018 |issn=1562-7020|url-access=subscription }}{{Cite journal |last1=Andrus |first1=Peter S |last2=Stothard |first2=J Russell |last3=Kabatereine |first3=Narcis B |last4=Wade |first4=Christopher M |date=2023-07-21 |title=Comparing shell size and shape with canonical variate analysis of sympatric Biomphalaria species within Lake Albert and Lake Victoria, Uganda |journal=Zoological Journal of the Linnean Society |volume=199 |issue=3 |pages=713–722 |doi=10.1093/zoolinnean/zlad052 |issn=0024-4082|doi-access=free }} In the case of B. choanomphala, its commonly associated with having a lacustrine morphotype (morphotype-B), while the non-lacustrine morphotype (morphotype-A) is commonly mistaken for another African Biomphalaria species, B. sudanica.
