> Bellamya japonica (von Martens 1861)
    "Cipangopaludina" japonica

> Habitat & Distribution
Although native to southeast Asia, Bellamya japonica (and the closely-related B. chinensis) were first introduced to North America in the late 1890s and have now spread throughout the United States, especially in New England and the Midwest (Cordeiro 2002).  Several large and healthy populations were established in South Carolina prior to 2000 - Lake Greenwood, Jonesville Reservoir, and "Muddy Creek" in northern Spartanburg County (presumably Mud Creek, a tributary of Lake Bowen.)  "Giant Asian Snails" were spotlighted in the July-August 1995 issue of "South Carolina Wildlife" magazine (Anon. 1995).  I thank my colleague Jay Cordeiro for calling my attention to two additional early reports, Benson et al. 2001 and Anon. 2001.

In 2002 we confirmed a large population of Bellamya in Lake Marion just north of Charleston, in 2004 we received reports of the snail in North Carolina (at upper Lake Norman) and in 2005 we discovered a large population in North Carolina's High Rock / Tuckertown Reservoir.  The snails seem to have spread down the Catawba River from Lake Norman, appearing at South Carolina's Lake Wylie in 2005 and at Great Falls in 2006.  The year 2006 also brought us word of a Bellamya introduction into Monticello Reservoir north of Jenkinsville and the first appearance of the snail in the Savannah River system - Lake Hartwell at Clemson.  The maps available as PDF downloads below are both quite out of date.

> Ecology & Life history
“Water gardening” has become a popular hobby throughout much of the US.  The retail stores that have developed to supply hobbyists with pond liners, pumps, goldfish and ornamental lilies also commonly stock “mystery snails” or “trap-door snails” to clarify the water.  These are almost always Bellamya.  They seem to reproduce well in artificial environments, and I suspect that most recent introductions in this country are simply excess snails casually dumped by water gardeners.

That Bellamya populations can, in fact, clarify the water in small ornamental ponds attests to their efficiency as filter-feeders.  They probably also graze, or at least scavenge excess fish food (Raut 1986).  But they most certainly do not consume macrophytes, lest their popularity with water gardeners who invest heavily in such plants should be short-lived.

Although the life cycle of naturalized American populations has not been characterized, Khan & Chaudhuri (1984) reported six-month maturation, followed by iteroparous reproduction, in an Indian population of Bellamya bengalensis (Bii of Dillon 2000: 156- 162). 

> Taxonomy & Systematics
The oldest literature sometimes refers japonica to the genus Viviparus.  Although the species is most commonly assigned to the genus “Cipangopaludina” here in the United States today, Smith (2000) pointed out that the genus Bellamya (Jousseaume 1886) is generally preferred throughout the Old World.  The characters used to differentiate Cipangopaludina (Hannibal 1912) appear to be variable or generally characteristic of viviparids reaching a relatively large size.

The two North American species, B. chinensis and B. japonica, have sometimes been confused or even synonymized.  But Smith found no morphological overlap between the former (bearing a shell with more rounded shoulders) and the latter (with a more turreted shell), and recommended that the specific distinction be retained.

> Essay #1
Bellamya was mentioned parenthetically in a 29Oct03 essay I posted to the FWGNA web site on invasive viviparids in South Carolina.  The info is a bit obsolete, but there are links to several additional photos.

> Essay #2
I posted several news items regarding Bellamya, as well as some links, photos, and other resources in a message to the FWGNA group on 6Oct05.

>Pretty photo
Living B. japonica, courtesy of Chris Lukhaup.

 
>Maps of Bellamya distribution
Click the small map to enlarge it, or download the state-specific PDFs



North Carolina (PDF)

South Carolina (PDF)

> References
Anon. (1995) Exotic Aquatics show up in South Carolina.  South Carolina Wildlife, July-August, p. 48.  Anon. (2001) Technical Comittee Reports/Concerns, Exotics.  American Fiseries Society Southern Division Newsletter, July, p. 16.  Benson, A. J., Fuller, P. L, & Jacono, C. C. (2001)  Summary report of nonindigenous aquatic species in US Fish & Wildlife Service Region 4.  USFWS, Arlington, Va, p. 60.  Clench, W. & Fuller, S. (1965) The genus Viviparus in North America. Occas. Pprs. on Mollusks, Mus. Comp. Zool. Harvard, 2, 385-412.  Cordeiro, J. R. (2002)  Proliferation of the Chinese mystery snail, Cipangopaludina chinensis malleata (Reeve, 1863) throughout Connecticut [Abstract].  Program and Abstracts of the 68th Meeting of the American Malacological Society, Charleston, SC (R. T. Dillon, ed.)  p. 37.  Jokinen, E. (1982)  Cipangopaludina chinensis (Gastropoda: Viviparidae) in North America.  Nautilus 96: 89 – 95.  Khan, R., & S. Chaudhuri (1984)  The population and production ecology of a freshwater snail Bellamya bengalensis (Lamarck) (Gastropoda: Viviparidae) in an artificial lake of Calcutta, India. Bull. Zool. Surv. India, 5: 59-76.  Raut, S. (1986)  Inhibition of fish growth by the freshwater snail Bellamya bengalensis. Environ. Ecol., 4: 332-333.  Smith, D.G. (2000)  Notes on the taxonomy of introduced Bellamya (Gastropoda: Viviparidae) species in northeastern North America.  Nautilus 114: 31-37.