Biomphalaria sudanica is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod belonging to the family Planorbidae, the ram's horn snails.[1] 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.[2]

Biomphalaria sudanica
Apical and apertural view of Biomphalaria sudanica
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Superorder: Hygrophila
Family: Planorbidae
Genus: Biomphalaria
Species:
B. sudanica
Binomial name
Biomphalaria sudanica
(Martens, 1870)

Habitat and distribution edit

Biomphalaria sudanica is an African species found in freshwater habitats such as rivers, streams, ponds and the Great African Lakes.[2] 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.

The distribution of Biomphalaria sudanica mainly occurs in East Africa:[3]

Ecology and behavior edit

Biomphalaria sudanica 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 sudanica 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.

Biomphalaria sudanica is found in shallow water near the shoreline in Lake Albert.[5] Despite being a pulmonate, Biomphalaria sudanica is well adapted to use the oxygen from water (but not as well as Planorbis). This ability is useful for living in swamp habitats.[10] The population density of Biomphalaria sudanica varies during the year. The highest population density of Biomphalaria sudanica is in Lake Ziway, Ethiopia from June to August, at the end of rainy season.[11] It was experimentally detected under laboratory conditions that shells of Biomphalaria sudanica are bigger in waters with higher concentration of calcium than in waters with low calcium.[3]

Conservation status and biological importance edit

Biomphalaria sudanica 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. Biomphalaria sudanica is an intermediate host for Schistosoma mansoni[12] and for Schistosoma rodhaini.[13]

Infestation with schistosomes in the Lake Victoria basin is about 1%,[13] but can be up to 50% in the case of Schistosoma mansoni and up to 6% in Schistosoma rodhaini in some localities.[13]

Phylogeny edit

A cladogram showing the phylogenic relations of species in the genus Biomphalaria:[14]

Biomphalaria

However, upon further analysis of the African Biomphalaria species found B. sudanica is a part of the "Nilotic Species Complex" and is more closely related to B. alexandrina, B. smithi and B. stanleyi, than the previously thought, B. choanomphala.[6]

 
Phylogenetic Tree of the African Biomphalaria species

Ecological phenotypes edit

Biomphalaria sudanica has been the subject of multiple ecological and genetic studies. However, unlike B. choanomphala[15][16] and B. pfeifferi,[17] there have been no reports of ecological phenotypic variation in B. sudanica snails. However, in the case of B. sudanica, it is often misidentified as the non-lacustrine ecophenotype (morphotype-A) of B. choanomphala at Lake Victoria.[16][18][19][20] This is due to B. choanomphala inhabiting a large number of different ecosystems in Lake Victoria and the non-lacustrine morphotype commonly occurs in similar habitats (Common Water Hyacinth Eichhornia crassipes) [21] of B. sudanica snails in Lake Albert, Lake Kyoga and Lake Ziway.

 
Comparing the shell morphologies of Biomphalaria sudanica and B. choanomphala.[20]

References edit

  1. ^ Brown, David S (1994-05-26). Freshwater Snails Of Africa And Their Medical Importance. CRC Press. doi:10.1201/9781482295184. ISBN 978-1-4822-9518-4.
  2. ^ a b Pointier, J. P.; David, P.; Jarne, P. (2005). "Biological invasions: The case of planorbid snails". Journal of Helminthology. 79 (3): 249–256. doi:10.1079/JOH2005292. PMID 16153319. S2CID 11158571.
  3. ^ a b Brodersen, J. (2003). "The effect of calcium concentration on the crushing resistance, weight and size of Biomphalaria sudanica (Gastropoda: Planorbidae)". Hydrobiologia. 490: 181–186. doi:10.1023/A:1023495326473. S2CID 23230744.
  4. ^ WILLIAMS, S. N.; HUNTER, P. J. (September 1967). "Distribution of Biomphalaria Species in Sudan". Nature. 215 (5108): 1408. Bibcode:1967Natur.215.1408W. doi:10.1038/2151408a0. ISSN 0028-0836. PMID 6069731. S2CID 4194570.
  5. ^ a b Kazibwe, F.; Makanga, B.; Rubaire-Akiiki, C.; Ouma, J.; Kariuki, C.; Kabatereine, N. B.; Booth, M.; Vennervald, B. J.; Sturrock, R. F.; Stothard, J. R. (2006). "Ecology of Biomphalaria (Gastropoda: Planorbidae) in Lake Albert, Western Uganda: Snail distributions, infection with schistosomes and temporal associations with environmental dynamics". Hydrobiologia. 568: 433–444. doi:10.1007/s10750-006-0224-y. S2CID 7704584.
  6. ^ a b JØRGENSEN, ASLAK; KRISTENSEN, THOMAS K.; STOTHARD, J. RUSSELL (October 2007). "Phylogeny and biogeography of African Biomphalaria (Gastropoda: Planorbidae), with emphasis on endemic species of the great East African lakes". Zoological Journal of the Linnean Society. 151 (2): 337–349. doi:10.1111/j.1096-3642.2007.00330.x. ISSN 1096-3642.
  7. ^ John, R.; Ezekiel, M.; Philbert, C.; Andrew, A. (2008). "Schistosomiasis transmission at high altitude crater lakes in western Uganda". BMC Infectious Diseases. 8: 110. doi:10.1186/1471-2334-8-110. PMC 2518556. PMID 18694485.
  8. ^ Goll, P. H. (April 1982). "Seasonal changes in the distribution ofBiomphalaria sudanica sudanica(Martens) in Lake Zwai, Ethiopia". Annals of Tropical Medicine & Parasitology. 76 (2): 159–164. doi:10.1080/00034983.1982.11687522. ISSN 0003-4983. PMID 7092369.
  9. ^ Erko, B.; Balcha, F.; Kifle, D. (2006). "The ecology of Biomphalaria sudanica in Lake Ziway, Ethiopia". African Journal of Ecology. 44 (3): 347–352. Bibcode:2006AfJEc..44..347E. doi:10.1111/j.1365-2028.2006.00615.x.
  10. ^ Jones, J. D. (1964). "Respiratory gas exchange in the aquatic pulmonate, Biomphalaria sudanica". Comparative Biochemistry and Physiology. 12 (3): 297–310. doi:10.1016/0010-406X(64)90061-1.
  11. ^ Erko, B.; Balcha, F.; Kifle, D. (2006). "The ecology of Biomphalaria sudanica in Lake Ziway, Ethiopia". African Journal of Ecology. 44 (3): 347–352. Bibcode:2006AfJEc..44..347E. doi:10.1111/j.1365-2028.2006.00615.x.
  12. ^ Black, C. L.; Mwinzi, P. N. M.; Muok, E. M. O.; Abudho, B.; Fitzsimmons, C. M.; Dunne, D. W.; Karanja, D. M. S.; Secor, W. E.; Colley, D. G. (2010). Bethony, Jeffrey M (ed.). "Influence of Exposure History on the Immunology and Development of Resistance to Human Schistosomiasis Mansoni". PLOS Neglected Tropical Diseases. 4 (3): e637. doi:10.1371/journal.pntd.0000637. PMC 2843635. PMID 20351784.  
  13. ^ a b c Steinauer, M. L.; Mwangi, I. N.; Maina, G. M.; Kinuthia, J. M.; Mutuku, M. W.; Agola, E. L.; Mungai, B.; Mkoji, G. M.; Loker, E. S. (2008). Knight, Matty (ed.). "Interactions between Natural Populations of Human and Rodent Schistosomes in the Lake Victoria Region of Kenya: A Molecular Epidemiological Approach". PLOS Neglected Tropical Diseases. 2 (4): e222. doi:10.1371/journal.pntd.0000222. PMC 2291567. PMID 18414646.  
  14. ^ Dejong, R. J.; Morgan, J. A.; Paraense, W. L.; Pointier, J. P.; Amarista, M.; Ayeh-Kumi, P. F.; Babiker, A.; Barbosa, C. S.; Brémond, P.; Pedro Canese, A.; De Souza, C. P.; Dominguez, C.; File, S.; Gutierrez, A.; Incani, R. N.; Kawano, T.; Kazibwe, F.; Kpikpi, J.; Lwambo, N. J.; Mimpfoundi, R.; Njiokou, F.; Noël Poda, J.; Sene, M.; Velásquez, L. E.; Yong, M.; Adema, C. M.; Hofkin, B. V.; Mkoji, G. M.; Loker, E. S. (2001). "Evolutionary relationships and biogeography of Biomphalaria (Gastropoda: Planorbidae) with implications regarding its role as host of the human bloodfluke, Schistosoma mansoni". Molecular Biology and Evolution. 18 (12): 2225–2239. doi:10.1093/oxfordjournals.molbev.a003769. PMID 11719572.
  15. ^ Standley, Claire J.; Wade, Chris; Stothard, J. Russell (2011-10-24). "A Fresh Insight into Transmission of Schistosomiasis: A Misleading Tale of Biomphalaria in Lake Victoria". PLOS ONE. 6 (10): e26563. Bibcode:2011PLoSO...626563S. doi:10.1371/journal.pone.0026563. ISSN 1932-6203. PMC 3200340. PMID 22046308.
  16. ^ a b Zhang, Si-Ming; Bu, Lijing; Laidemitt, Martina R.; Lu, Lijun; Mutuku, Martin W.; Mkoji, Gerald M.; Loker, Eric S. (2018-05-09). "Complete mitochondrial and rDNA complex sequences of important vector species of Biomphalaria, obligatory hosts of the human-infecting blood fluke, Schistosoma mansoni". Scientific Reports. 8 (1): 7341. Bibcode:2018NatSR...8.7341Z. doi:10.1038/s41598-018-25463-z. ISSN 2045-2322. PMC 5943310. PMID 29743617.
  17. ^ Plam, Maria; Jørgensen, Aslak; Kristensen, Thomas K.; Madsen, Henry (April 2008). "SympatricBiomphalariaspecies (Gastropoda: Planorbidae) in Lake Albert, Uganda, show homoplasies in shell morphology". African Zoology. 43 (1): 34–44. doi:10.1080/15627020.2008.11407404. ISSN 1562-7020. S2CID 84525018.
  18. ^ Standley, Claire J; Goodacre, Sara L; Wade, Christopher M; Stothard, J Russell (2014-11-19). "The population genetic structure of Biomphalaria choanomphala in Lake Victoria, East Africa: implications for schistosomiasis transmission". Parasites & Vectors. 7 (1): 524. doi:10.1186/s13071-014-0524-4. ISSN 1756-3305. PMC 4254209. PMID 25406437. S2CID 255983772.
  19. ^ Standley, Claire J.; Vounatsou, Penelope; Gosoniu, Laura; Jørgensen, Aslak; Adriko, Moses; Lwambo, Nicholas J. S.; Lange, Charles N.; Kabatereine, Narcis B.; Stothard, J. Russell (2012-01-03). "The distribution of Biomphalaria (Gastropoda: Planorbidae) in Lake Victoria with ecological and spatial predictions using Bayesian modelling". Hydrobiologia. 683 (1): 249–264. doi:10.1007/s10750-011-0962-3. ISSN 0018-8158. S2CID 254549615.
  20. ^ a b Andrus, Peter S; Stothard, J Russell; Kabatereine, Narcis B; Wade, Christopher M (2023-07-21). "Comparing shell size and shape with canonical variate analysis of sympatric Biomphalaria species within Lake Albert and Lake Victoria, Uganda". Zoological Journal of the Linnean Society. 199 (3): 713–722. doi:10.1093/zoolinnean/zlad052. ISSN 0024-4082.
  21. ^ Plummer, M. L. (2005). "Impact of Invasive Water Hyacinth (Eichhornia crassipes) on Snail Hosts of Schistosomiasis in Lake Victoria, East Africa". EcoHealth. 2: 81–86. doi:10.1007/s10393-004-0104-8. S2CID 29955129.].

Further reading edit