【印度扁卷螺】
印度扁卷螺属（学名：Indoplanorbis）为一种会呼吸空气的淡水螺的一个属，属于软体动物门腹足纲有肺类扁蜷科的动物。本属的唯一物种为印度扁卷螺（Indoplanorbis exustus）。本物种广泛分布于热带地区，包括印度、缅甸、斯里兰卡、印度尼西亚、泰国、马来西亚以及中国大陆的云南等地，主要生活于湖泊沿岸带、池塘以及沼泽地等淡水和微咸水域。本物种是多种寄生吸虫的重要中间宿主。其入侵性本质及环境的高容耐度使之成为医学上及兽医学上的重要研究课题。
==分类==
尽管本物种有着悠久的历史和广泛的地理分布范围，牠们一直都被认为是属内唯一的物种；而过往亦有文献建议本属跟其他关系较密切的属合并。然而，Liu et al. (2010)根据系统地理学研究，发现在系统发育方面，印度分支和东南亚分支之间有相当的分歧；加上栖息地和寄生虫学的差异，表明这个物种实际可能由多于一个物种构成。
从系统发育的角度看，与本属关系最密切的是Bulinus属。
==分布==
印度扁卷螺本身是一种淡水螺，在中亚的伊朗与阿富汗，南亚的印度、尼泊尔及斯里兰卡均见其踪影。在东南亚，例如：泰国)，甚至远至阿拉伯地区及非洲均见其踪影。
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 affect agriculture, natural ecosystems, human health or commerce. Therefore it has been suggested that this species be given top national quarantine significance in the USA.
===生物地理学===
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.
==简述==
与其他同属扁卷螺科的物种一样，其外壳都是平旋壳，但其实是螺把壳上下颠倒来揹在身上，使左旋的外壳看起来像是右旋。本物种的外壳呈圆盘形，所以whorl (mollusc)大小的增长很快。每个螺层的高比其阔增长得较快：其阔约为 5-25 mm，其高约为 4.5-13 mm。
Planorbella duryi 跟 Biomphalaria pfeifferi 的外壳非常相似。
基于本物种的广泛地理分布，Indoplanorbis exustus have been studied, such as its calcium regulation and its hemocytes.
==生态学==
当印度扁卷螺被圈养时，可以以莴苣及菠菜Parashar 1986来圈养。有时候其膳食会辅以羊肝Parashar 1986，在繁殖时可提供一般宠物鼠的食粮Parashar 1986。
=== 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 tolerance of adult 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 vegetation mats. It is possible it could be transported by birds.
=== Life cycle ===
Indoplanorbis exustus is a hermaphroditic invasive 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.
===捕食者===
现时本物种并没有已知的天敌，不过有文献透过实验去测试一些物种会否进食印度扁卷螺的卵。Raut & Aditya (2002)在实验里让一种属于南美洲福寿螺科的Pomacea bridgesii去攻击和进食印度扁卷螺的卵，以期望未来可以让这种福寿螺来控制印度扁卷螺的数量。
===寄生虫===
Indoplanorbis is of economic importance in that it is responsible for the transmission of several species of the genus Schistosoma 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 and S. spindale, as well as other trematodes such as Echinostoma spp. and some spirorchids. A third species of Schistosoma, S. indicum (Montgomery, 1906), is also transmitted by I. exustus. Other snails have been implicated in transmission of these three Schistosoma species (such as Lymnaea luteola, a host for S. indicum and S. nasale, and L. acuminata, a host for S. nasale and S. spindale), I. exustus is the most important host for S. nasale and S. spindale, as well as for S. indicum in certain regions. I. 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 malayanum - as the first intermediate host
*似锥低颈吸虫 Hypoderaeum conoideum - as the first intermediate host
*巨片吸虫 Fasciola gigantica
* Paramphistomum mehrai
* Paramphistomum explanatum
* Gastrodiscus secundus
* Petagifer srivastavi
* Plasmiorchis orientalis
* Pseudodiscus collinsi
* Gastrothylax crumenifer
* Enterohaemotrema paleorticum
* Cotylophoron cotylophorum
* Cotylophoron indica
* Cotylophoron bhaleraoi
* Cotylophoron mathurapurensis
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.
===毒理学===
一种在印度生长的大戟科植物红雀珊瑚（lang|la|Pedilanthus tithymaloides）可用作植物性杀螺剂，有助对抗印度扁卷螺。
黄果茄的酒精提取物亦可对本物种（LC50 = 198.00 mg/L and LC90 = 236.80 mg/L）。
此外，另一种大戟科物种虎刺梅（Euphorbia milii），其杂交物种株的乳汁对于本物种的活跃度有所抑制，也可作杀螺剂使用。除了虎刺梅的杂交种，印度的科学家Singh & Sunil在2005年发表的文献亦研究过黄花夹竹桃（Cascabela thevetia）、黑板树（Alstonia scholaris）两种夹竹桃科植物及另一种较常见的大戟科植物一品红（Euphorbia pulcherrima）的乳汁对印度扁卷螺的抑制效果。
==参考文献==
本条目包括部分来自以CC 2.0分享的参考文献开源内容。
==外部连结==
* Indoplanorbis exustus
* title=Indoplanorbis exustus
* 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.
*  pmc = .