Radix natalensis

''Radix natalensis'' is a species of freshwater snail, an aquatic gastropod mollusc in the family Lymnaeidae.

This species occurs widely in Africa. It is a major intermediate host for ''Fasciola gigantica'' in Africa. Placement of this species in the genus ''Radix'' was confirmed by Correa et al. (2010).

Distribution

''Radix natalensis'' is a widespread species in Africa, occurring from northern Africa to southern Africa:

* Northern Africa: Algeria, Tunisia, Egypt, Sudan. There are also findings of distribution of ''Radix natalensis'' in Algeria 8–10,000 years ago. In Egypt it has been detected in water bodies of the Nile Delta.
* Western Africa: Benin, Burkina Faso, Côte d'Ivoire, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Niger, Nigeria and Senegal, Sarr A., Kinzelbach R. & Diouf M. (2011, in press). "Diversité spécifique et écologie des mollusques continenatux de la basse vallée du Ferlo (Sénégal). pecific diversity and ecology of continental molluscs from the Lower Ferlo Valley (Senegal). ''MalaCo'' 7: 8 pp
PDF
.
* Eastern Africa: Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Malawi, Mozambique, Somalia, Tanzania, Uganda, Zambia and Zimbabwe.
* Central Africa: Angola, Cameroon, Central African Republic, Chad, Democratic Republic of the Congo, Republic of the Congo, Equatorial Guinea and Gabon.
* Southern Africa: Botswana, Namibia, South Africa and Rhodesia.
* Madagascar

The type locality is in "pools in Port Natal", which today is Durban, South Africa.

Description

''Radix natalensis'' was described by the German scientist and traveller Christian Ferdinand Friedrich Krauss in 1848.

The shape of the shell is elongate ovoid.Wright C. A. (1963). "The freshwater gastropod mollusca of Angola". ''Bulletin of the British Museum (Natural History)'' 10(8): 447–528. 16 plates
page 493
The shell is colorless or light brown in color. The height of the aperture covers about 3/4 of the shell height. The lip of the aperture is thin and sharp. The umbilicus is closed. The width of the shell is about 5.75–7 mm. The height of the shell is 4.6–19.2 mm.

The reproductive system and radula was described by Wright (1963
in detail

Ecology

''Radix natalensis'' lives in permanent water bodies. They prefer clear, slow-running water with low salinity and abundant vegetation. An estimated density of ''Radix natalensis'' in a natural habitat in Tanzania was 34 snails per m². The snails lived mainly in the shallow water in depths of 0–4 cm, mainly between 20–30 cm from the shoreline. They prefer plant detritus or bedrock as a substrate.

Laboratory experiments have shown that some larger snails of ''Radix natalensis'' can survive on a wooden surface without water for up to 21 days. Some smaller snails of ''Radix natalensis'' have survived desiccation on a soil surface up to 60 days on "black" soil. Some smaller snails of ''Radix natalensis'' were able to survive for up to 90 days on soil among sedges ''(Cyperus)'' or in the "black" soil exposed to sun or in the soil with stones.

Parasites

This species has been found to be an intermediate host of both ''Fasciola hepatica'' and ''Fasciola gigantica''. Overall, rates of snail infection vary between 10% and 40%. The highest infection rate was found to be in summer and this may be a factor responsible for lowering snail density in this season.
Parasites of ''Radix natalensis'' include:
* ''Fasciola hepatica''
* ''Fasciola gigantica''Soliman M. F. M. (2008). "Epidemiological review of human and animal fascioliasis in Egypt". '' The Journal of Infection in Developing Countries'' 2(3): 182–189
abstractPDF
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* ''Trichobilharzia'' sp.
* some cercaria from Echinostomatidae
* some xiphidiocercaria from Plagiorchiidae
* four trematode larvae in Zambia

Predators of ''Radix natalensis'' include leeches '' Helobdella nilae'' and ''Alboglossiphonia conjugata''.

Snails of the non-indigenous species ''Marisa cornuarietis'' eliminated ''Radix natalensis'' and other two native snail species from a small pond in Tanzania in an experiment in 1982.

Oil extract of the gum myrrh ''Commiphora myrrha'' has molluscicidal activity against ''Radix natalensis''.

Phylogeny

A cladogram shows the phylogenic relations of species in the genus ''Radix'':

Synonyms

* ''Limnaea (Biformiana) cameroni'' Bourguignat, 1890 (a junior synonym)
* ''Limnaea (Biformiana) kynganica'' Bourguignat, 1890 (a junior synonym)
* ''Limnaea (Biformiana) zanzibarica'' Bourguignat, 1890 (a junior synonym)
* ''Limnaea (Limosiana) alexandrina'' Bourguignat, 1883 (a junior synonym)
* ''Limnaea (Limosiana) alexandrina var. gracilis'' Bourguignat, 1883 (a junior synonym)
* ''Limnaea (Raffrayana) raffrayi'' Bourguignat, 1883
* ''Limnaea (Stagnaliana) caillaudi'' Bourguignat, 1883 (a junior synonym)
* ''Limnaea acroxa'' Bourguignat, 1883 (a junior synonym)
* ''Limnaea aethiopica'' Bourguignat, 1883 (a junior synonym)
* ''Limnaea africana'' Bourguignat, 1883
* ''Limnaea africana var. azaouadensis'' Germain, 1909 (a junior synonym)
* ''Limnaea africana var. elata'' Germain, 1919 (a junior synonym)
* ''Limnaea africana var. gouidimouniensis'' Germain, 1916 (basionym)
* ''Limnaea africana var. kambaensis'' Germain, 1911 (a junior synonym)
* ''Limnaea africana var. kouloaensis'' Germain, 1911 (a junior synonym)
* ''Limnaea anceyana'' Preston, 1910 (a junior synonym)
* ''Limnaea arabica'' E. A. Smith, 1894
* ''Limnaea benguellensis'' Morelet, 1867 (original combination)
* ''Limnaea bocageana'' Morelet, 1867 (a junior synonym)
* ''Limnaea caillaudi'' Bourguignat, 1883 Bourguignat J. R. (1883). "Histoire malacogie de l'abyssinie". '' Annales Des Sciences Naturelles (Zoologie)'' (6)15
1
162
89Plate 10
figs. 100–101.(a junior synonym)
* ''Limnaea chudeaui'' Germain, 1907 (a junior synonym)
* ''Limnaea damarana'' O. Boettger, 1910 (junior subjective synonym)
* ''Limnaea debaizei'' Bourguignat, 1887 (a junior synonym)
* ''Limnaea electa'' E. A. Smith, 1882 (a junior synonym)
* ''Limnaea elmeteitensis'' E.A. Smith, 1894 (a junior synonym)
* ''Limnaea gravieri'' Bourguignat, 1885
* ''Limnaea hovarum'' Tristram, 1863 (a junior synonym)
* ''Limnaea humerosa'' E. von Martens, 1897 (a junior synonym)
* ''Limnaea jouberti'' Bourguignat, 1888 (a junior synonym)
* ''Limnaea kempi'' Preston, 1912 (junior synonym)
* ''Limnaea laurenti'' Bourguignat, 1888 (a junior synonym)
* ''Limnaea lavigeriana'' Bourguignat, 1888 (a junior synonym)
* ''Limnaea natalensis'' F. Krauss, 1848 (superseded combination)
* ''Limnaea nyansae'' E. von Martens, 1892 (a junior synonym)
* ''Limnaea orophila'' Morelet, 1864 (junior synonym)
* ''Limnaea suarezensis'' Dautzenberg, 1895 (a junior synonym)
* ''Limnaea undussumae'' E. von Martens, 1897 (a junior synonym)
* ''Limnaea undussumae var. courteti'' Germain, 1904 (a junior synonym)
* ''Limnaea vignoni'' Germain, 1909 (a junior synonym)
* ''Limnaeus auricularius var. ribeirensis'' Reibisch, 1865 (a junior synonym)
* ''Limnaeus benguellensis'' Morelet, 1867 (a junior synonym)
* ''Limnaeus bocageanus'' Morelet, 1867 (a junior synonym)
* ''Limnaeus dakaensis'' Sturany, 1898
* ''Limnaea perrieri'' Bourguignat, 1881
* ''Limnaea raffrayi'' Bourguignat, 1883
* ''Lymnaea vatonnei'' Bourguignat, 1868
* ''Lymnaea'' (''Radix'') ''natalensis''
* ''Limnaeus natalensis'' Krauss, 1848
** ''Limnaeus natalensis var. exsertus'' von Martens, 1866 (junior synonym)

References

This article incorporates CC-BY-3.0 text from the reference.

External links

*
* See pages 110, 111–114, 568.

{{Taxonbar, from=Q5412202

Lymnaeidae
Gastropods described in 1848
Taxa named by Christian Ferdinand Friedrich Krauss