''Bulinus nasutus'' is a species of

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

freshwater snail with a sinistral shell, an aquatic gastropod

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the family

Planorbidae 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 instea ...

, the ramshorn snails and their allies.

Subspecies

* ''Bulinus nasutus nasutus'' * ''Bulinus nasutus productus'' Mandahl-Barth, 1960

Distribution

The distribution of ''Bulinus nasutus'' includes three countries in East Africa: *

Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi ...

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...

including

Zanzibar Zanzibar (; ; ) is an insular semi-autonomous province which united with Tanganyika in 1964 to form the United Republic of Tanzania. It is an archipelago in the Indian Ocean, off the coast of the mainland, and consists of many small islan ...

and

Pemba Island Pemba Island ( ar, الجزيرة الخضراء ''al-Jazīra al-khadrā'', literally "The Green Island"; sw, Pemba kisiwa) is a Tanzanian island forming part of the Zanzibar Archipelago, lying within the Swahili Coast in the Indian Ocean. Geo ...

Brown D. S. (1994). ''Freshwater Snails of Africa and their Medical Importance''.

Taylor & Francis Taylor & Francis Group is an international company originating in England that publishes books and academic journals. Its parts include Taylor & Francis, Routledge, F1000 (publisher), F1000 Research or Dovepress. It is a division of Informa ...

. . *

Uganda }), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The sou ...

Type locality is

Bagamoyo Bagamoyo, is a historic coastal town founded at the end of the 18th century, though it is an extension of a much older (8th century) Swahili settlement, Kaole. It was chosen as the capital of German East Africa by the German colonial administra ...

, now in Tanzania.

Description

The width of the shell is 12 mm. The height of the shell is 25 mm. The diploid

chromosome number Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectivel ...

is 2n = 36.

Ecology

''Bulinus nasutus'' lives in

temporary pool Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe ...

s, ditches and burrow-pits. High concentration of

chloride The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride sa ...

(468-2220 ppm Cl) have been found in pools inhabited by ''Bulinus nasutus'' in Tanzania. ''Bulinus nasutus'' can aestivate in the dry mud for about 5–8 months. Respiration of ''Bulinus nasutus'' during aestivation is probably aerobic. They aestivate on margins of pools, and thus stop aestivation only in optimal conditions, when the pool has much water. Webbe (1962, 1965)Webbe G. (1965). "Transmission of bilharziasis. 1. Some essential aspects of snail population dynamics and their study". ''

Bulletin of the World Health Organization The ''Bulletin of the World Health Organization'' is a monthly public health journal published by the World Health Organization that was established in 1947. Articles are published in English and abstracts are available in Arabic, Chinese, Englis ...

'' 33: 147-153. described population dynamics of ''Bulinus nasutus'' in Tanzania. Mature snails lay eggs during the whole life span, primarily immediately after the main rainfall. Snails 8 weeks old, whose shell is about 8 mm in height, are mature and can lay eggs. However they require more than 12 months of life and 1-2 aestivation periods in order to reach their full size. This species is an intermediate host for: * '' Schistosoma bovis'' * ''

Schistosoma haematobium ''Schistosoma haematobium'' (urinary blood fluke) is a species of digenetic trematode, belonging to a group (genus) of blood flukes (''Schistosoma''). It is found in Africa and the Middle East. It is the major agent of schistosomiasis, the most ...

'' - it is the main intermediate host of ''Schistosoma haematobium'' in northwestern Tanzania * '' Echinostome'' spp.

References

External links

* Coles G. C. (1969). "Observations on weight loss and oxygen uptake of aestivating ''Bulinus nasutus'', an intermediate host of ''Schistosoma haematobium''". '' Annals of Tropical Medicine and Parasitology'' 63: 393-398. * Harris R. A., Preston T. M. & Southgate V. R. (1993). "Purification of an agglutinin from the haemolymph of the snails ''Bulinus nasutus'' and demonstration of related proteins in other ''Bulinus'' spp." '' Parasitology 106: 127-136. * Matovu D. S. & Nditi H. P. (1978). "Laboratory experiments on the effect of aestivation on oviposition in ''Bulinus'' (''Physopsis'') ''nasutus''". ''Proceedings of the International Congress on Schistosomiasis'', Cairo, Egypt, 1975: 515-519. Cairo: Ministry of Health. * McClelland W. F. (1965). "Development of ''S. haematobium'' in ''Bulinus'' (''P.'') ''nasutus''. '' Reports of the East African Institute for Medical Research'' 1963–64: 15. * Pringle G., Otieno L. H. & Chimtawi M. B. (1971). "Notes on the morphology, susceptibility to ''S. haematobium'' and genetic relationships of ''Bulinus'' (''P.'') ''globosus'' and ''B.'' (''P.'') ''nasutus'' from north-eastern Tanzania". '' Annals of Tropical Medicine and Parasitology'' 65: 211-219. * Stothard J. R. & Rollinson D. (1997). "Partial DNA sequences from the mitochondrial cytochrome oxidase subunit I (COI) gene can differentiate the intermediate snail hosts ''Bulinus globosus'' and ''B. nasutus'' (Gastropoda: Planorbidae)". '' Journal of Natural History'' 31(5): 727-737. . * Sturrock B. M. (1967). "The effect of infection with ''Schistosoma haematobium'' on the growth and reproduction rates of ''Bulinus'' (''P.'') ''nasutus productus''. '' Annals of Tropical Medicine and Parasitology'' 61: 321-325. * Sturrock B. M. (1968). "Resistance of ''B.'' (''P.'') ''nasutus productus'' to infection by ''S. haematobium''". '' Annals of Tropical Medicine and Parasitology'' 62: 393-397. {{Taxonbar, from=Q4996455 Bulinus Gastropods described in 1879