Heterogen japonica
| Heterogen japonica | |
|---|---|
_Figure_2.jpg) | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Order: | Architaenioglossa |
| Family: | Viviparidae |
| Genus: | Heterogen |
| Species: | H. japonica |
| Binomial name | |
| Heterogen japonica Eduard von Martens, 1861 | |
| Synonyms | |
| |
Heterogen japonica, sometimes known as the Japanese mystery snail, is a species of freshwater snail in the family Viviparidae. While native to Japan, Korea, and Taiwan, the snail is invasive to the United States and possibly other countries.[1]
Description
Heterogen japonica has a large globose shell with an operculum covering its aperture. The shell typically has 7 to 8 whorls and a spire at a 50º to 55º angle. Along the outside of the shell are fine ridges. Juveniles have fine hairs along the periostracum. The color of the shells is typically brown or tan, typically getting darker as the snail ages.[2]
H. japonica is commonly confused with Cipangopaludina chinensis, known as the Chinese mystery snail, due to many similarities in form and an overlapping invasive range.[1][3]
Habitat and distribution
Heterogen japonica has only been found in freshwater bodies, such as lakes, ponds, and slow-moving rivers. The substrates of its habitats are typically sandy to muddy with dense amounts of vegetation.[1] Within their native range, they are often found in rice paddy fields.[2]
The snail is native to Japan, Korea, and Taiwan, but has become invasive to at least the United States. H. japonica was first described in the United States in the late 1800s by biologist Willard M. Wood who found possible specimens in Asian food markets in San Francisco. However, biologist Harold Hannibal later identified the specimens as another freshwater snail, Margarya laeta.[4] Hannibal later found snails in an irrigation ditch in San Joaquin Valley that he identified a H. japonica, but the specimens were lost and cannot be verified. Due to similarities to Cipangopaludina chinensis and morphological variation with the species, it is possible that these reports were misidentifications.[3] The snail was first officially identified through genetic testing in the United States in 2000 along the east coast[1] and later on the west coast in 2022. The cryptic morphology causes the possibility that its invasive range may be larger than reported, especially in regions were C. chinensis is invasive.[3]
Ecology
Heterogen japonica is a grazing snail that feeds mostly on bacterial materials, such as detritus and compost sludge.[5]
References
- 1 2 3 4 "https://invasions.si.edu/nemesis/species_summary/-493". invasions.si.edu. Retrieved 2026-08-15.
{{cite web}}: External link in|title= - 1 2 "Japanese mysterysnail (Cipangopaludina japonica) - Species Profile". USGS Nonindigenous Aquatic Species Database. Retrieved 2026-08-15.
- 1 2 3 Abeyrathna, Wijesooriya; Sanders, Shawn; Barreto, Ashley; Davinack, Andrew (2023). "First genetically confirmed report of the Japanese mystery snail, Heterogen japonica (Martens, 1861) from California more than a century after its first introduction" (PDF). BioInvasions Records. 12 (2): 501–511. doi:10.3391/bir.2023.12.2.14.
- ↑ Hannibal, H (1911). "Further notes on Asiatic viviparas in California". The Nautilus. 25: 31–32.
- ↑ Kurihara, Y.; Kadowaki, K. -I. (1988-08-01). "Effect of different ecological conditions on the mud snail (Cipangopaludina japonica) in submerged paddy soil". Biology and Fertility of Soils. 6 (4): 292–297. doi:10.1007/BF00261015. ISSN 1432-0789.