Biomphalaria pfeifferi

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 pfeifferi
Drawing of apical, apertural and umbilical view of the shell of Biomphalaria pfeifferi.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Superorder:	Hygrophila
Family:	Planorbidae
Genus:	Biomphalaria
Species:	B. pfeifferi
Binomial name
Biomphalaria pfeifferi (Krauss, 1848)[1]

This snail is a medically important pest,^[2] because of transferring the disease schistosomiasis.^[3]

Distribution

Biomphalaria pfeifferi is an African species. It has recently expanded its native range to the Arabian Peninsula and Madagascar.^[2]

Distribution of Biomphalaria pfeifferi include:

• Western Africa: Senegal^[4]
• Eastern Africa: Kenya^[3]
• Southern Africa: Botswana^[5] and South Africa.^[1]

The type locality is in Umgeni Valley, KwaZulu-Natal, South Africa^[1] (in the times of the description it was the British Colony of Natal).

Phylogeny

A cladogram showing phylogenic relations of species in the genus Biomphalaria:^[6]

Biomphalaria

Biomphalaria stanleyi Biomphalaria pfeifferi Biomphalaria camerunensis Nilotic species complex Biomphalaria sudanica Biomphalaria choanomphala Biomphalaria alexandrina Biomphalaria smithi Biomphalaria glabrata Biomphalaria straminea complex Biomphalaria kuhniana Biomphalaria straminea Biomphalaria straminea Biomphalaria intermedia Biomphalaria amazonica Biomphalaria sp. Biomphalaria tenagophila Biomphalaria occidentalis Biomphalaria prona Biomphalaria andecola Biomphalaria sp. (? Biomphalaria havanensis) Biomphalaria sp. (? Biomphalaria havanensis) Biomphalaria temascalensis Biomphalaria obstructa Biomphalaria helophila Biomphalaria peregrina Biomphalaria schrammi

Mating system

B. pfeifferi is hermaphroditic, and genetic analyses performed both at the family and population levels indicate high self-fertilization rates.^[7] However, B. pfeifferi exhibits only a low level of inbreeding depression.^[7]

Ecology

Biomphalaria pfeifferi can survive up to 16 hours in anaerobic water using lactic acid fermentation.^[8]

In Kenya, B. pfeifferi is positively associated with the common blue water-lily Nymphaea caerulea (the two species occur together).^[3]

Parasites

Parasites of Biomphalaria pfeifferi include the following 11 species found in Tanzania:^[9]

• Schistosoma mansoni^[9][10]
• undescribed clinostomatid^[9]
• two species undescribed strigea^[9]
• Cercaria porteri^[9]
• Cercaria blukwa^[9]
• two species of undescribed echinostome^[9]
• Cercaria lileta^[9]
• Cercaria obscurior^[9]
• Cercaria bulla^[9]

Control

In Kenya, releasing the edible American crayfish Procambarus clarkii as an introduced species has helped eliminate the mollusc, which it feeds on, as well as provided a new source of food and income,^[3][11] but may also be impacting the environment by reducing the amount of native aquatic plants.^[12]

The seeds of the tree Balanites aegyptiaca have a molluscicide effect on Biomphalaria pfeifferi.^[13]

Substance	Route	LC50	Reference
Powder of crude kernels of Balanites aegyptiaca	immersion(?)	60 ppm	[13]
Acetone extract of powder of the kernels of Balanites aegyptiaca	immersion(?)	172,40 ppm	[13]
Ethanol extract of the powder of kernels of Balanites aegyptiaca	immersion(?)	84,15 ppm	[13]

Ethanolic extract of the fruits of Dalbergia sissoo (family Leguminosae) exhibited molluscicidal effect against eggs of Biomphalaria pfeifferi.^[14]