Oncomelania is a genus of very small tropical freshwater snails, aquatic gastropod mollusks in the family Pomatiopsidae.
These Oncomelania snails are distantly related to the marine periwinkle, and more closely related to the small marine snails of the family Rissoidae.
There are two[2] species in the genus Oncomelania:
Woodruff et al. (1999) recognized also the following species:
Japanese Red List Data Book (2006) recognizes also the following additional species:
This genus has not yet become established in the USA, but it 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.[7]
About the origin and evolution history of Oncomelania, Davis (1979)[3] proposed a Gondwanan origin for the Pomatiopsidae, with rafting to mainland Asia via the Indian Craton after break-up of Gondwanan and colonization of South-East Asia and China. It is hypothesized that Oncomelania snails, arrived in southwestern China from Indian before the second (major) Tibetan orogeny (2.5 Ma), then evolved and spread down their respective river systems, to mainland of China, Indonesia and Philippines. Although mutation rate calibrations using fossil data is impossible here, many studies have demonstrated the confidence that molecular data can provide reasonable estimates of divergence time.[8] Data by Zhao et al. (2010)[8] suggested that the two subspecies of Oncomelania hupensis began to diverse as early about 2–6 Ma based on the invertebrate ITS substitution rate range. Zhao et al. (2010)[8] did not find any strong molecular and fossil evidences about Oncomelania evolution, but the reported Oncomelania fossil found in Guangxi (1 Ma) by Nils Hjalmar Odhner in 1930 and geological movement make this diversification time reasonable. It provides a new insight into the Oncomelania evolution history although the substitution rate needs to be verified with new fossil and molecular data in future study.[8]
Various Oncomelania species are significant medically, because they can serve as vectors for two serious human diseases: they can carry the schistosomiasis blood fluke parasite, and the paragonimus lung fluke parasites.
The miracidia reproduce asexually through sporocyst stages within these intermediate hosts, resulting in the production of many free-swimming cercariae.[9]
This article incorporates CC-BY-2.0 text from the reference[9] and CC-BY-2.5 text from the reference[8]
Oncomelania is a genus of very small tropical freshwater snails, aquatic gastropod mollusks in the family Pomatiopsidae.
These Oncomelania snails are distantly related to the marine periwinkle, and more closely related to the small marine snails of the family Rissoidae.
Oncomelania es un género de moluscos gasterópodos de la familia Pomatiopsidae. Varias especies de Oncomelania están involucradas en el ciclo de vida de los trematodos del género Schistosoma, parásitos de la sangre, causantes de la enfermedad esquistosomiasis, así como del género Paragonimus, parásitos de los pulmones, causantes de la paragonimosis.
Datos: Q5225925
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Oncomelania es un género de moluscos gasterópodos de la familia Pomatiopsidae. Varias especies de Oncomelania están involucradas en el ciclo de vida de los trematodos del género Schistosoma, parásitos de la sangre, causantes de la enfermedad esquistosomiasis, así como del género Paragonimus, parásitos de los pulmones, causantes de la paragonimosis.
Oncomelania is een geslacht van weekdieren uit de klasse van de Gastropoda (slakken).
Oncomelania is een geslacht van weekdieren uit de klasse van de Gastropoda (slakken).
釘螺泛指所有釘螺屬（學名：Oncomelania）的物種，是一种在田间生活的腹足綱軟體動物。釘螺屬曾經屬於觿螺科（Hydrobiidae）[3]及麂眼螺總科[4]，今屬截螺總科盖螺科[5][6]。
钉螺外壳小，呈圆锥形，有螺层7个左右，像一个小螺丝钉，因而得名。壳面光滑或有各种粗细不同的直棱；壳口呈卵圆形，周围完整，略向外翻，有角质厣片。（厣：yǎn）
钉螺由螺壳和软体两部分组成。软体部分的前部为头、颈、足和外套膜，后部是内脏包。
釘螺屬物種基本上可以分為下列兩種[2]：
Woodruff et al. (1999)也確認以下物種：
Japanese Red List Data Book (2006) recognizes also the following additional species:
表面有纵肋者称肋壳钉螺，壳长约10毫米，宽约4毫米，生存於湖沼或水网地区；壳面光滑者为光壳钉螺，比肋壳钉螺稍小，长、宽分别为6毫米和3毫米，多见於山丘地区。
钉螺属软体动物，有雌、雄之分，水陆两栖，活躍於15~20℃度的气温，主要靠吃藻类而生存，多孳生于水分充足、有机物丰富、杂草丛生、潮湿荫蔽的灌溉沟或河边浅滩；通常生活在水线上下，冬季随气温下降深入地面下数厘米蛰伏越冬。钉螺也可在地面生活，但活动范围有限，速度缓慢。
钉螺的活动范围并不大，但可随水流漂到很远的地方，也可附着在杂草或其他漂浮物上而扩散到远处。人们穿的草鞋、牛蹄间隙、打水草或移种水生植物（如芦苇、茭白等）、运送鱼苗等也能使钉螺扩散。钉螺扩散后，遇到适合的环境便“安家落户”、孳生繁殖，形成新的钉螺孳生地。
钉螺的寿命一般为1年，有的钉螺可存活2-3年，甚至超过5年。感染了血吸虫毛蚴的钉螺叫「感染螺」，感染螺的寿命一般不到1年，最长也可存活2年多。
钉螺是日本血吸虫幼虫的主要宿主[11]，所以水患期间，消灭钉螺是防治血吸虫的一个重要环节。
オンコメラニア属、学名 Oncomelania は、盤足目・イツマデガイ科に分類される巻貝の属のひとつである。
日本・中国[2]・フィリピン・インドネシアなどの淡水域に分布する。本属に属する種には、日本住血吸虫の中間宿主が含まれている。
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