Hierarchy contributed by the species page author
Hierarchy combined from multiple sources
|Scientific Name||Indoplanorbis exustus (Deshayes, 1834)|
|Synonym||Planorbis exustus Deshayes, 1834|
|Synonym||Indoplanorbis exustus Deshayes, 1834|
Indoplanorbis exustus is a hermaphroditic invasive snail species with high fecundity. Within a year of introduction, the snail is able to colonize habitats with well established populations of other pulmonate and prosobranch snails.
At water temperatures in excess of 15°C, the snail matures, and at an optimum temperature of 30 °C each snail can lay up to 800 eggs. The eggs are laid in clusters, with 2-43 eggs and an average of 20 eggs in each cluster. Over it's life span of 4 months, this snail lays about 60 egg clusters.
On average: 4 months.
The shell of this species is dorso-ventrally flat and, 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. The aperture is oval to round and shell is thin.
A similar shell is seen in Planorbella duryi and Biomphalaria pfeifferi.
In the wild, it feeds on fresh and decaying aquatic plants.
In captivity, Indoplanorbis exustus can be fed with lettuce and spinach. Feeding with sheep's liver is recommended for maintenance and feeding with synthetic food (M/s Hindustan Lever's rat food) is recommended for breeding.
Eggs of Indoplanorbis exustus were experimentally predated and destroyed by Pomacea bridgesii. Raut & Aditya (2002) hypothetized that Pomacea bridgesii could be a potential biocontrol agent for Indoplanorbis exustus.
Indoplanorbis is a widely distributed monotypic genus.
In spite of its long history and wide geographical range, it is thought that Indoplanorbis is a widely distributed monotypic genus. However according to phylogeography research by Liu et al. (2010), 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.
Meier-Brook (1984) adopted an African (Gondwanan) 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.
Aqueous extract of a common medicinal plant of India Pedialanthus tithymaloide (Euphorbiaceae) 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).
This species of snail is found attached to aquatic plants in small ponds, pools, tanks, lakes as well as stagnant pools of water in rivers, and reservoirs. It is also seen less commonly in man-made habitats such as paddy fields, ditches, etc. 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 tolerance 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).
Indoplanorbis exustusis is a widely distributed species, known from Iran, the Arabian Peninsula (Saudi Arabia, Oman and Socotra Island in Yemen), China, Malay Peninsula and Archipelago, Myanmar, Pakistan, Persia, Sumatra, Celebes, Java, Malaya, Thailand, Indonesia, Malaysia, Vietnam, Bangladesh, India, Sri Lanka and Nepal (Yueying Liu 1979, Subba Rao 1989).
This is a very common species. Wherever it occurs, it has been seen in very high density. Personal unpublished studies have shown that population densities of this species reach to more than 20 individuals per square metre.
It is a vector and intermediate host for many parasites of domestic and wild animals. Some important parasites that use the snail as intermediate hosts are Artyfechinostomum sufrartyfex, Schistosoma indicum, Schistosoma nasalis, Schistosoma spindalis, Fasciola gigantica, Paramphistomum mehrai, Paramphistomum explanatum, Gastrodiscus secundus, Petagifer srivastavi, Plasmiorchis orientalis, Pscudodiscus collinsi, Gastrothylax crumenifer, Enterohaemotrema paleorticum, Cotylophoron cotylophorum, Cotylophoron indica, Cotylophoron bhaleraoi, Cotylophoron mathurapurensis, and Echinostoma sp. (Yueying Liu 1979, Subba Rao 1989).
Indoplanorbis exustus is the most important host for Schistosoma nasale and Schistosoma spindale, as well as for Schistosoma indicum in certain regions. Indoplanorbis exustus may be the sole natural intermediate host for these three Schistosoma species on the Indian sub-continent.
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.
Invasiveness: This species has a capacity for self-fertilization and shows an exceptionally high fecundity - both of which probably underlies the invasive potential of this species.
Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2012
Assessor/s: Budha, P.B., Dutta, J. & Daniel, B.A.
Reviewer/s: Madhyastha, A., Dey, A., Molur, S. & García, N.
Contributor/s: Neubert, E. & Amr, Z.S.S.
No major specific threats are known for the species.
It is used extensively in research.