Indoplanorbis exustus
Encyclopedia
Indoplanorbis exustus is a species
of air-breathing freshwater snail
, an aquatic
pulmonate gastropod mollusk in the family
Planorbidae
, the ram's horn snails. The species is the sole member of its genus and is widely distributed across the tropics. It serves as an important intermediate host
for several trematode parasites. The invasive
nature and ecological tolerance of Indoplanorbis exustus add to its importance in veterinary and medical science.
research by Liu et al. (2010) revealed the phylogenetic depth of divergences between the Indian clades and Southeast Asian clades, together with habitat and parasitological differences suggest that Indoplanorbis exustus may comprise more than one species.
The most phylogenetically related genus to Indoplanorbis is genus Bulinus
.
of this species, like all planorbids is sinistral in coiling, but is carried upside down and thus appears to be dextral. The shell of Indoplanorbis exustus is discoid with rapidly increasing whorls
. Each whorl is higher than it is wide. The width of the shell is 5-25 mm. The height of the shell is 4.5-13 mm.
Similar shell has also Planorbella duryi
and Biomphalaria pfeifferi
.
Because of its wide distribution was the Indoplanorbis exustus subject of various studies including: the regulation of calcium after shell damage (1980), Hemocyte
s of Indoplanorbis exustus were under research by Mahilini & Rajendran (2008).
The type locality of Indoplanorbis exustus is marshes on the coast of Malabar in southwestern India.
Indoplanorbis exustus is a common snail across Southeast Asia and the Indian sub-continent. The snail is also found in the Middle East (Oman
and Socotra
) and Nigeria and the Ivory Coast; these findings were attributed by Brandt (1974) to recent introductions by human activities (Brandt's view has been frequently cited in the literature on Indoplanorbis). In contrast to Asia, the well documented appearance of the snail in Africa (e.g., Nigeria and Ivory Coast) and more recently (2002) in the Lesser Antilles, is almost certainly the result of introductions through human activities over the last 50–100 years.
This species is already established in the USA, and is considered to represent a potentially serious threat as a pest, an invasive species
which could negatively effect agriculture, natural ecosystems, human health or commerce. Therefore it has been suggested that this species be given top national quarantine
significance in the USA.
n) origin for Indoplanorbis with rafting to Asia since the Cretaceous
on the northward migrating Indian craton; this author also considered a Europe to Southwest Asia tract or an Africa to South India dispersal. Morgan et al. (2002) attributed the occurrence of Indoplanorbis in India to colonization (from Africa) via the Middle East land connection. Clearly the two different dispersal mechanisms imply very different chronologies; the Gondwanan vicariance hypothesis implies that proto-Indoplanorbis has been present in India since the late Eocene (35 Ma; India: Asia collision), whereas dispersal via
the Sinai-Levant suggests a Plio-Pleistocene
arrival. The results by Liu et al. (2010) indicated a radiation beginning in the late Miocene with a divergence of an ancestral bulinine lineage into Assam
and peninsular India clades. A Southeast Asian clade diverged from the peninsular India clade late-Pliocene; this clade then radiated at a much more rapid pace to colonize all of the sampled range of Indoplanorbis in the mid-Pleistocene.
is recommended fo maintenance and feeding with synthetic food (M/s Hindustan Lever's rat food) is recommended for breeding.
of adults snails is high while the resistance of juvenile snails is very low. Consequently, dispersal may occur in clumps of mud adhered to the bodies of cattle or across water in flotsam (vegetation mats), and possibly also attached to migratory birds (although this has not been observed for Indoplanorbis exustus).
snail species with high fecundity
. Within one year of introduction the snail is able to colonize habitats with well established populations of other pulmonate and prosobranch snails. The snail requires a water temperature in excess of 15 °C for maturation. At the optimum temperature of 30 °C each snail can lay up to 800 eggs. There is from 2 to 43 eggs in one cluster with an average 20 eggs in one cluster. The capacity for self-fertilization and high fecundity probably underlies the invasive potential of the species. The average life span of Indoplanorbis exustus is 4 months and during this time it lays about 60 egg clusters.
. Raut & Aditya (2002) hypothetized that Pomacea bridgesii could be a potential biocontrol
agent for Indoplanorbis exustus.
which infect cattle and cause reduced livestock
productivity. The snail is also of medical importance as a source of cercarial dermatitis among rural workers, particularly in India.
Indoplanorbis exustus is best known as the intermediate host responsible for the transmission
of Schistosoma nasale
Rao, 1933 and Schistosoma spindale
(Montgomery, 1906), as well as other trematodes such as Echinostoma
spp. and some spirorchids (Spirorchiidae
). A third species of Schistosoma, Schistosoma indicum
(Montgomery, 1906) is also transmitted by Indoplanorbis exustus. Although other snails have been implicated in transmission of these three Schistosoma spp. (e.g., Lymnaea luteola
is a host for Schistosoma indicum and Schistosoma nasale. Lymnaea acuminata
is an intermediate host for Schistosoma nasale and Schistosoma spindale), Indoplanorbis exustus is the most important host for Schistosoma nasale and Schistosoma spindale, as well as for Schistosoma indicum in certain regions. Indeed Indoplanorbis exustus may be the sole natural intermediate host for these three Schistosoma species on the Indian sub-continent.
Indoplanorbis exustus is also an intermediate host for:
Indoplanorbis exustus has been implicated in outbeaks of cercarial dermatitis in human populations in India, Laos, Malaysia and Thailand. Cercarial dermatitis results from the cutaneous allergic reaction in people exposed to larval schistosomes (cercariae) shed by infected snails into freshwater bodies such as lakes, ponds, and paddy fields. The cercariae cause pruritis and papular eruptions, with often severe secondary infections, as they attempt to infect a non-permissive definitive host and die in the skin.
) has molluscicidal
activity against Indoplanorbis exustus.
Ethanol extract of Solanum xanthocarpum has molluscicidal activity against Indoplanorbis exustus LC50 = 198.00 mg/l and LC90 = 236.80 mg/l.
The latex of Euphorbia milii
has molluscicidal activity against Indoplanorbis exustus that depends on its hybrid of the plant.
The molluscicidal activity of latex of Thevetia peruviana
, Alstonia scholaris
and Euphorbia pulcherrima against Indoplanorbis exustus was examined by Singh & Sunil (2005).
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of air-breathing freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....
, an aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
pulmonate gastropod mollusk in the family
Family
In human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence. In most societies it is the principal institution for the socialization of children...
Planorbidae
Planorbidae
Planorbidae, common name the ramshorn snails or ram's horn snails, is a family of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks....
, the ram's horn snails. The species is the sole member of its genus and is widely distributed across the tropics. It serves as an important intermediate host
Intermediate host
A secondary host or intermediate host is a host that harbors the parasite only for a short transition period, during which some developmental stage is completed. For trypanosomes, the cause of sleeping sickness, humans are the primary host, while the tsetse fly is the secondary host...
for several trematode parasites. The invasive
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
nature and ecological tolerance of Indoplanorbis exustus add to its importance in veterinary and medical science.
Taxonomy
Indoplanorbis exustus is the only known species in the genus Indoplanorbis. In spite of its long history and wide geographical range, it is thought that Indoplanorbis includes only a single species. However phylogeographyPhylogeography
Phylogeography is the study of the historical processes that may be responsible for the contemporary geographic distributions of individuals. This is accomplished by considering the geographic distribution of individuals in light of the patterns associated with a gene genealogy.This term was...
research by Liu et al. (2010) revealed the phylogenetic depth of divergences between the Indian clades and Southeast Asian clades, together with habitat and parasitological differences suggest that Indoplanorbis exustus may comprise more than one species.
The most phylogenetically related genus to Indoplanorbis is genus Bulinus
Bulinus
Bulinus is a genus of small tropical freshwater snails, aquatic gastropod mollusks in the family Planorbidae, the ramshorn snails and their allies....
.
Description
The shellGastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
of this species, like all planorbids is sinistral in coiling, but is carried upside down and thus appears to be dextral. The shell of Indoplanorbis exustus is discoid with rapidly increasing whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
. Each whorl is higher than it is wide. The width of the shell is 5-25 mm. The height of the shell is 4.5-13 mm.
Similar shell has also Planorbella duryi
Planorbella duryi
Planorbella duryi, common name the Seminole rams-horn, is a species of air-breathing freshwater snail, a pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.-Distribution:This species of snail is endemic to Florida, USA....
and Biomphalaria pfeifferi
Biomphalaria pfeifferi
Biomphalaria pfeifferi is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.This snail is a medically important pest, because of transferring the disease schistosomiasis....
.
Because of its wide distribution was the Indoplanorbis exustus subject of various studies including: the regulation of calcium after shell damage (1980), Hemocyte
Hemocyte
A hemocyte is a cell that plays a role in the immune system of invertebrates. It is found within the hemolymph.Hemocytes are phagocytes of invertebrates....
s of Indoplanorbis exustus were under research by Mahilini & Rajendran (2008).
Distribution
The freshwater snail Indoplanorbis exustus is found across India, Sri Lanka, Southeast Asia (for example Thailand), central Asia (Afghanistan), Arabia and Africa.The type locality of Indoplanorbis exustus is marshes on the coast of Malabar in southwestern India.
Indoplanorbis exustus is a common snail across Southeast Asia and the Indian sub-continent. The snail is also found in the Middle East (Oman
Oman
Oman , officially called the Sultanate of Oman , is an Arab state in southwest Asia on the southeast coast of the Arabian Peninsula. It is bordered by the United Arab Emirates to the northwest, Saudi Arabia to the west, and Yemen to the southwest. The coast is formed by the Arabian Sea on the...
and Socotra
Socotra
Socotra , also spelt Soqotra, is a small archipelago of four islands in the Indian Ocean. The largest island, also called Socotra, is about 95% of the landmass of the archipelago. It lies some east of the Horn of Africa and south of the Arabian Peninsula. The island is very isolated and through...
) and Nigeria and the Ivory Coast; these findings were attributed by Brandt (1974) to recent introductions by human activities (Brandt's view has been frequently cited in the literature on Indoplanorbis). In contrast to Asia, the well documented appearance of the snail in Africa (e.g., Nigeria and Ivory Coast) and more recently (2002) in the Lesser Antilles, is almost certainly the result of introductions through human activities over the last 50–100 years.
This species is already established in the USA, and is considered to represent a potentially serious threat as a pest, an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
which could negatively effect agriculture, natural ecosystems, human health or commerce. Therefore it has been suggested that this species be given top national quarantine
Quarantine
Quarantine is compulsory isolation, typically to contain the spread of something considered dangerous, often but not always disease. The word comes from the Italian quarantena, meaning forty-day period....
significance in the USA.
Biogeography
Meier-Brook (1984) adopted an African (GondwanaGondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
n) origin for Indoplanorbis with rafting to Asia since the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
on the northward migrating Indian craton; this author also considered a Europe to Southwest Asia tract or an Africa to South India dispersal. Morgan et al. (2002) attributed the occurrence of Indoplanorbis in India to colonization (from Africa) via the Middle East land connection. Clearly the two different dispersal mechanisms imply very different chronologies; the Gondwanan vicariance hypothesis implies that proto-Indoplanorbis has been present in India since the late Eocene (35 Ma; India: Asia collision), whereas dispersal via
the Sinai-Levant suggests a Plio-Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
arrival. The results by Liu et al. (2010) indicated a radiation beginning in the late Miocene with a divergence of an ancestral bulinine lineage into Assam
Assam
Assam , also, rarely, Assam Valley and formerly the Assam Province , is a northeastern state of India and is one of the most culturally and geographically distinct regions of the country...
and peninsular India clades. A Southeast Asian clade diverged from the peninsular India clade late-Pliocene; this clade then radiated at a much more rapid pace to colonize all of the sampled range of Indoplanorbis in the mid-Pleistocene.
Ecology
In captivity Indoplanorbis exustus can be fed for example by lettuce and spinach. Feeding with sheep's liverLiver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
is recommended fo maintenance and feeding with synthetic food (M/s Hindustan Lever's rat food) is recommended for breeding.
Habitat
The snail is found in small ponds, pools, and less commonly in rice paddy fields. The snail may also occur in semi-permanent pools formed in flooded areas of fields, where it can survive the dry season buried in mud. The desiccation toleranceDesiccation tolerance
Desiccation tolerance refers to the ability of an organism to withstand or endure extreme dryness, or drought-like conditions. Plants and animals living in arid or periodically arid environments such as temporary streams or ponds may face the challenge of desiccation, therefore physiological or...
of adults snails is high while the resistance of juvenile snails is very low. Consequently, dispersal may occur in clumps of mud adhered to the bodies of cattle or across water in flotsam (vegetation mats), and possibly also attached to migratory birds (although this has not been observed for Indoplanorbis exustus).
Life cycle
Indoplanorbis exustus is a hermaphroditic invasiveInvasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
snail species with high fecundity
Fecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...
. Within one year of introduction the snail is able to colonize habitats with well established populations of other pulmonate and prosobranch snails. The snail requires a water temperature in excess of 15 °C for maturation. At the optimum temperature of 30 °C each snail can lay up to 800 eggs. There is from 2 to 43 eggs in one cluster with an average 20 eggs in one cluster. The capacity for self-fertilization and high fecundity probably underlies the invasive potential of the species. The average life span of Indoplanorbis exustus is 4 months and during this time it lays about 60 egg clusters.
Predators
Eggs of Indoplanorbis exustus were experimentally predated and destroyed by Pomacea bridgesiiPomacea bridgesii
Pomacea bridgesii, common names the Spike-topped apple snail or Mystery snail, is a South American species of freshwater snail with gills and an operculum, an aquatic gastropod mollusk in the family Ampullariidae.-Subspecies:...
. Raut & Aditya (2002) hypothetized that Pomacea bridgesii could be a potential biocontrol
BioControl
BioControl is a peer-reviewed scientific journal published by Springer Science+Business Media covering all aspects of basic and applied research in biological control of invertebrate, vertebrate, and weed pests, and plant diseases. The journal was established in 1956 as Entomophaga and published by...
agent for Indoplanorbis exustus.
Parasites
Indoplanorbis is of economic importance in that it is responsible for the transmission of several species of the genus SchistosomaSchistosoma
A genus of trematodes, Schistosoma, commonly known as blood-flukes and bilharzia, includes flatworms which are responsible for a highly significant parasitic infection of humans by causing the disease schistosomiasis, and are considered by the World Health Organization as the second most...
which infect cattle and cause reduced livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
productivity. The snail is also of medical importance as a source of cercarial dermatitis among rural workers, particularly in India.
Indoplanorbis exustus is best known as the intermediate host responsible for the transmission
Transmission (medicine)
In medicine and biology, transmission is the passing of a communicable disease from an infected host individual or group to a conspecific individual or group, regardless of whether the other individual was previously infected...
of Schistosoma nasale
Schistosoma nasale
Schistosoma nasale is a species of digenetic trematode in the family Schistosomatidae.Schistosoma nasale was identified in 1933 by Dr. M. A. N...
Rao, 1933 and Schistosoma spindale
Schistosoma spindale
Schistosoma spindale is a species of digenetic trematode in the family Schistosomatidae. It causes intestinal schistosomiasis of cattle.The distribution of Schistosoma spindale include Sri Lanka, India, Bangladesh, Thailand, Malaysia and Laos....
(Montgomery, 1906), as well as other trematodes such as Echinostoma
Echinostoma
Echinostoma is an important genus that includes many parasites.Human echinostomiasis is an intestinal parasitic disease caused by one of at least sixteen trematode flukes from the genus Echinostoma. Found largely in southeast Asia and the Far East, mainly in cosmopolitan areas. It has extensive...
spp. and some spirorchids (Spirorchiidae
Spirorchiidae
Spirorchiidae is a family of digenetic trematodes. They are parasites of turtles. Disease caused by them is commonly called spirorchiidiosis.- Genera :Genera in the family Spirorchiidae include:* Amphiorchis** Amphiorchis solus* Hapalotrema...
). A third species of Schistosoma, Schistosoma indicum
Schistosoma indicum
Schistosoma spindale is a species of digenetic trematode in the family Schistosomatidae.The parasite is widespread in India and other Asian countries....
(Montgomery, 1906) is also transmitted by Indoplanorbis exustus. Although other snails have been implicated in transmission of these three Schistosoma spp. (e.g., Lymnaea luteola
Lymnaea luteola
Radix luteola is a species of freshwater snail, an aquatic gastropod mollusc in the family Lymnaeidae.Placement of this species in the genus Radix have been confirmed by Correa et al. .There exist two forms:...
is a host for Schistosoma indicum and Schistosoma nasale. Lymnaea acuminata
Lymnaea acuminata
Lymnaea acuminata is a species of freshwater snail, an aquatic gastropod mollusc in the family Lymnaeidae.- Parasites :Lymnaea acuminata is the first intermediate host for trematodes Schistosoma nasale and for Schistosoma spindale....
is an intermediate host for Schistosoma nasale and Schistosoma spindale), Indoplanorbis exustus is the most important host for Schistosoma nasale and Schistosoma spindale, as well as for Schistosoma indicum in certain regions. Indeed Indoplanorbis exustus may be the sole natural intermediate host for these three Schistosoma species on the Indian sub-continent.
Indoplanorbis exustus is also an intermediate host for:
- Artyfechinostomum malayanumArtyfechinostomum malayanumArtyfechinostomum malayanum is a species of digenetic trematode in the family Echinostomatidae.The known first intermediate host of Artyfechinostomum malayanum include freshwater snails Indoplanorbis exustus and Gyraulus convexiusculus....
- as the first intermediate host - Hypoderaeum conoideumHypoderaeum conoideumHypoderaeum conoideum is a species of digenetic trematode in the family Echinostomatidae.The known first intermediate host of Hypoderaeum conoideum include freshwater snails Planorbarius corneus, Indoplanorbis exustus, Lymnaea stagnalis, Lymnaea limosa, Radix ovata and Radix...
- as the first intermediate host - Fasciola giganticaFasciola giganticaFasciola gigantica is a parasitic flatworm of the class Trematoda, which causes tropical fascioliasis. It is regarded as one of the most important single platyhelminth infections of ruminants in Asia and Africa...
- Paramphistomum mehrai
- Paramphistomum explanatum
- Gastrodiscus secundus
- Petagifer srivastavi
- Plasmiorchis orientalis
- Pseudodiscus collinsi
- Gastrothylax crumenifer
- Enterohaemotrema paleorticum
- Cotylophoron cotylophorum
- Cotylophoron indica
- Cotylophoron bhaleraoi
- Cotylophoron mathurapurensis
- EchinostomaEchinostomaEchinostoma is an important genus that includes many parasites.Human echinostomiasis is an intestinal parasitic disease caused by one of at least sixteen trematode flukes from the genus Echinostoma. Found largely in southeast Asia and the Far East, mainly in cosmopolitan areas. It has extensive...
sp.
Indoplanorbis exustus has been implicated in outbeaks of cercarial dermatitis in human populations in India, Laos, Malaysia and Thailand. Cercarial dermatitis results from the cutaneous allergic reaction in people exposed to larval schistosomes (cercariae) shed by infected snails into freshwater bodies such as lakes, ponds, and paddy fields. The cercariae cause pruritis and papular eruptions, with often severe secondary infections, as they attempt to infect a non-permissive definitive host and die in the skin.
Toxicology
Aqueous extract of a common medicinal plant of India Pedialanthus tithymaloide (EuphorbiaceaeEuphorbiaceae
Euphorbiaceae, the Spurge family are a large family of flowering plants with 300 genera and around 7,500 species. Most are herbs, but some, especially in the tropics, are also shrubs or trees. Some are succulent and resemble cacti....
) has molluscicidal
Molluscicide
Molluscicides, also known as snail baits and snail pellets, are pesticides against molluscs, which are usually used in agriculture or gardening to control gastropod pests like slugs and snails that can damage crops by feeding on them....
activity against Indoplanorbis exustus.
Ethanol extract of Solanum xanthocarpum has molluscicidal activity against Indoplanorbis exustus LC50 = 198.00 mg/l and LC90 = 236.80 mg/l.
The latex of Euphorbia milii
Euphorbia milii
Euphorbia milii is a woody, succulent species of Euphorbia native to Madagascar. The species name commemorates Baron Milius, once governor of Réunion, who introduced the species to France in 1821...
has molluscicidal activity against Indoplanorbis exustus that depends on its hybrid of the plant.
The molluscicidal activity of latex of Thevetia peruviana
Thevetia peruviana
Thevetia peruviana is a plant native to central and southern Mexico and Central America. It is a close relative of Nerium oleander, giving it one common name as Yellow Oleander, and is also called lucky nut in the West Indies....
, Alstonia scholaris
Alstonia scholaris
Alstonia scholaris Alstonia scholaris Alstonia scholaris (Apocynaceae, commonly called Blackboard tree, Indian devil tree, Ditabark, Milkwood pine, White cheesewood and Pulai; syn. Echites scholaris L. Mant., Pala scholaris L...
and Euphorbia pulcherrima against Indoplanorbis exustus was examined by Singh & Sunil (2005).
External links
- Baker F. C. (1945). The molluscan family Planorbidae. The University of Illinois Press, Urbana. 196-201.
- Raut S. K. (1986). "Disease transmitting snails. II. Population studies of Indoplanorbis exustus Deshayes." First year PRS Thesis in Science, University of Calcutta.
- Raut S., Rahman M. & Samanta S. (1992). "Influence of temperature on survival, growth and fecundity of the freshwater snail Indoplanorbis exustus (Deshayes)". Mem Inst Oswaldo Cruz 87: 15-19.
- Yapi Y., N'Goran K. E., Salia D., Cunin P. & Bellec C. (1994). "Population dynamics of Indoplanorbis exustus (Deshayes, 1834) (Gastropoda: Planorbidae), an exotic freshwater snail recently discovered at Yamoussoukro (Ivory Coast)". Journal of Molluscan Studies 60(1): 83-87. doi:10.1093/mollus/60.1.83.