Chinese mystery snail

Taxonomy of the introduced populations of Oriental mystery snails is confusing and there are many scientific names in use. argues that Cipangopaludina is a subgenus of Bellamya; however, because most North American literature does not use the genus Bellamya to refer to these introduced snails, Oriental mystery snails discussed here are referred to by the name Cipangopaludina. Literature cited in the USGS database regarding the Chinese mystery snail may employ the following names: Cipangopaludina chinensis, Cipangopaludina chinensis malleatus, Cipangopaludina chinensis malleata, Viviparus malleatus, Viviparus chinensis malleatus, Bellamya chinensis and Bellamya chinensis malleatus. == Description ==

Species of the genus Cipangopaludina can be identified by their relatively large globose shells and concentrically marked opercula. The shell is conical and thin but solid, with a sharp apex and relatively higher spire and distant body whorl. This species has a small and round umbilicus and the spire is produced at an angle of 65–80°. Cipangopaludina chinensis exhibits light coloration as a juvenile and olive green, greenish brown, brown or reddish brown pigmentation as an adult. The inner coloration is white to pale blue. The surface of the shell is smooth with clear growth lines. The shell has 6.0–7.0 whorls. Bellamya chinensis is a large gastropod species generally in shell height and in shell width, the largest being in height and wide. The shell height can reach up to . Cipangopaludina chinensis has a width to height ratio of 0.74–0.82. The aperture is ovoid with a simple outer lip and inner lip. In juveniles, the last shell whorl displays a distinct carina, and the shell contains grooves with 20 striae/mm between each groove. Juveniles also have a detailed pattern on their periostracum consisting of two apical and three body whorl rows of hairs with long hooks on the ends, distinct ridges and many other hairs with short hooks. The shell of Cipangopaludina chinensis grows allometrically (the height increasing faster than the width) and does so at a decreased rate in comparison with Cipangopaludina japonica, such that the adult shell is less elongate than that of its congener. The radula also may differ between Cipangopaludina japonica and Cipangopaludina chinensis, but there is so much variation even within one species that it is not a good diagnostic characteristic. However, as a general guide, in one North American population, the radula of Cipangopaludina chinensis had seven small cusps on the marginal tooth and a large central cusp with four small cusps on either side. Mystery snails (unlike apple snails) do not possess a siphon. They give live birth, and like all aquatic snails they only have one set of tentacles. == Distribution ==

Though native to East Asia from the tropics of Indochina to northern China, this species has established itself in North America. The native range is from Southeast Asia to Japan and eastern Russia. The nonindigenous distribution in the USA include: • various ponds in Connecticut and Massachusetts; • Potomac River, Maryland; Great Lakes Region: The first record of Cipangopaludina chinensis malleata in the Great Lakes dates from some time between 1931 and 1942 from the Niagara River, which flows into Lake Ontario. records occurrences of populations of Cipangopaludina chinensis in the drainages of Lake Erie, Lake Ontario and Lake Michigan, from the states of Michigan, Indiana, Ohio, Wisconsin, and New York. Cipangopaludina chinensis.jpg|In Naperville, Illinois, USA United Kingdom The Chinese mystery snail was first recorded in England from a ditch in the Pevensey Levels in Sussex in September 2018 and early in 2022 a second population was reported on iNaturalist from Southampton Common. This was investigated by Natural England and the snails were found to be present in a boating lake and an ornamental lake on the Common. How the snails were introduced is unknown but it was either through release from aquaria or from snails imported for food. == Ecology ==

This species prefers freshwater lakes with soft, muddy or silty bottoms, Life cycle Reproduction is initiated sexually. This species is ovoviviparous. As an intermediate host for: • Echinochasmus elongatus • Echinochasmus redioduplicatus • Echinochasmus rugosus • Eupariphium ilocanum • Eupariphium recurvatum • Echinostoma macrorachis • Echinostoma cinetorchis in Korea - this parasite may infect humans. • It is also a common host to larvae of echinostomes in the Kinmen islands. == Human use ==

This species constitutes one of the three predominant freshwater snails found in Chinese markets. This snail is extensively used as part of the human diet in most places in China because the meat of the snail is considered delicious, being rich in nutrition, with high protein and low fat content. ==References==