Tarebia granifera, common name (in the aquarium industry) the quilted melania, is a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Thiaridae.
This snail is native to south-eastern Asia, but it has become established as an invasive species in multiple other areas.
Subspecies Subspecies of Tarebia granifera include: Tarebia granifera granifera (Lamarck, 1822) Tarebia granifera mauiensis Brot, 1877"Tarebia granifera mauiensis Brot, 1877". EOL, accessed 10 August 2010.
Description
A detailed account of the anatomy of Tarebia granifera was given by R. Tucker Abbott in 1952Tucker Abbott R. (1952). "A study of an intermediate snail host (Thiara granifera) of the Oriental lung fluke (Paragonimus)". Proceedings of the United States National Museum 102: 71-116. together with notes on its biology and bionomics. A dissection guide was provided by Malek (1962).Malek E. A. (1962). Laboratory Guide and Notes for Medical Malacology. 1–154. Burgess Publishing Company, Minneapolis.
The maximum height of adult shells of this species from South Africa is from 18.5 mm to 25.1 mm, while in Puerto Rico they can reach up to 35 mm.
Two color forms of Tarebia granifera exist, one has a pale brown body whorl and a dark spire (see photo on the right) and in the other the shell is entirely dark brown to almost black (see photo on the left). Intermediate forms exist.
Distribution Indigenous distribution The indigenous distribution of this species includes the general area of these countries: India, Sri Lanka, Philippines, Hawaii, southern Japan, Society Islands,Tarebia granifera (Lamarck, 1822), Last modified 3 August 2005, accessed 27 December 2007, Internet Archive: . Taiwan,Chen K-J. (2003). "A preliminary study on the reproductive ecology of the freshwater snail Tarebia granifera (Lamarck, 1822) (Prosobranchia: Thiaridae) in Jinlun River, South Eastern Taiwan". MSc thesis, National Sun Yat Sen University, Taiwan. 56 pp. Hong Kong, Thailand.Ukong S., Krailas D., Dangprasert T. & Channgarm P. (2007). "Studies on the morphology of cercariae obtained from freshwater snails at Erawan waterfall, Erawan national park, Thailand". The Southeast Asian Journal of Tropical Medicine and Public Health 38(2): 302–312. PDF.
Nonidigenous distribution Tarebia granifera has become invasive on at least three continents: North and South America and Africa. Initial introductions were presumably via the aquarium trade.
Americas: This species occurs in several states of the U.S.: Florida, Texas, Hawaii and IdahoUnited States Geological Survey. (2008). Tarebia granifera. USGS Nonindigenous Aquatic Species Database, Gainesville, FL. <https://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=1039 > Revision Date 4 February 2009. Many Caribbean islands: Puerto RicoChaniotis B. N., Butler J. M., Ferguson F. F. & Jobin W. R. (1980). "Bionomics of Tarebia granifera (Gastropoda: Thiaridae) in Puerto Rico, an Asian vector of Paragonimiasis westermani". Caribbean Journal of Science 16: 81–89. PDF CubaGutierrez A., Perera G., Yong M. & Fernandez J. A. (1997). "Relationships of the Prosobranch snails Pomacea paludosa, Tarebia granifera and Melanoides tuberculata with the abiotic environment and freshwater snail diversity in the central region of Cuba". Malacologial Review 30: 39–44. – along with Physella acuta it is the most common freshwater snail in Cuba The Dominican RepublicVargas M., Gomez J. & Perera G. (1991). "Geographic expansion of Marisa cornuarietis and Tarebia granifera in the Dominican Replublic". J. Med. & Appl. Malacol. 3: 69–72. Saint Lucia Martinique since 1991 Staňková H. (6 December 2006). "Sladkovodní plži překvapivě rychle kolonizují nové oblasti". on-line. Central America: Mexico El Hatillo Municipality, Miranda, Venezuela
Africa: South Africa The Tarebia granifera was reported from South Africa (and Africa) for the first time in 1999 in northern KwaZulu-Natal though it was probably introduced sometime prior to 1996. In the 10 years since its discovery it has spread rapidly, particularly northwards, into Mpumalanga province, the Kruger National Park and Eswatini.
This spread will doubtless continue into northern South Africa, Moçambique, Zimbabwe and beyond. It has not been possible to calculate the rate of dispersal.
Asia: Israel (non-indigenous)
Ecology Habitat In the South Africa, the snail has colonized different types of habitat, from rivers, lakes and irrigation canals to concrete lined reservoirs and ornamental ponds. It reaches high densities, up to 21 000 m2, and is likely to impact on the entire indigenous benthos of the natural waterbodies of the region – more so than any other invasive freshwater invertebrate known from the South Africa. The South African indigenous thiarids Thiara amarula, Melanoides tuberculata, and Cleopatra ferruginea are considered particularly vulnerable.
Most localities in South Africa (93%) lie below an altitude of 300 m above sea level where an estimated area of 39 500 km2 has been colonized. The only known localities outside this area are the Umsinduzi River in Pietermaritzburg and its confluence with the Umgeni River which lie closer to 500 m. R. Tucker Abbott (1952) noted that on Guam Island, Tarebia granifera occurred in streams and rivers at 983 m altitude but that these watercourses were consistently above 24 °C indicating that temperature may be an important determinant of distribution.
Tarebia granifera also occurs in several estuaries along the KwaZulu-Natal coast. Prominent among these is the dense population (±6038 m2) found at a salinity of 9.98‰ (28.5% sea water) in Catalina Bay, Lake St Lucia, iSimangaliso Wetland Park, KwaZulu-Natal. These records show that Tarebia granifera is able to colonize brackish and moderately saline habitats and reach high densities there. From observations in Puerto Rico it was suggested that snails could survive temporarily saline conditions for several weeks by burying themselves in the substratum, emerging when fresh water returned.
In common with other Thiaridae, Tarebia granifera is primarily a benthic species and in South Africa has been collected on a variety of substrata in both natural and artificial waterbodies, e.g. sand, mud, rock, concrete bridge foundations and the concrete walls and bottoms of reservoirs, irrigation canals and ornamental ponds. Many of these habitats were vegetated and the associated vegetation included many types of emergent monocotyledons (e.g. Cyperus papyrus, Scirpus sp., Typha sp., Phragmites sp.) and dicotyledons (e.g. Ceratophyllum demersum, Potamogeton crispus, Nymphaea nouchali). Where densities are high, Tarebia granifera may also occur on marginal, trailing vegetation and the floating Common Water Hyacinth Eichhornia crassipes as well. It favours turbulent water and tolerates current speeds up to 1.2m.s−1 and possibly greater. This habitat range is similar to that recorded for Tarebia granifera in Puerto Rico.
The major interest in Tarebia granifera outside Asia today is its invasive ability and its impact on indigenous benthic communities in colonized waterbodies. The pollution tolerance value is 3 (on scale 0–10; 0 is the best water quality, 10 is the worst water quality).Young S.-S., Yang H.-N., Huang D.-J., Liu S.-M., Huang Y.-H., Chiang C.-T. & Liu, J.-W. (2014). "Using Benthic Macroinvertebrate and Fish Communities as Bioindicators of the Tanshui River Basin Around the Greater Taipei Area – Multivariate Analysis of Spatial Variation Related to Levels of Water Pollution". International Journal of Environmental Research and Public Health 11(7): 7116–7143. .
Typically half or more of these snails were buried in the sediments and were not visible from the surface. This was also noticed in aquaria where they actively buried themselves in sand. Exact proportion of population of Tarebia granifera that is buried at any time is not known. There is also not known how long can snails remain buried.
Tarebia granifera will die at the temperature 7 °C in aquaria, but they do not live in water temperature under 10 °C in the wild.
Dispersal It is probable that dispersal of Tarebia granifera from one waterbody or river catchment to another occurs passively via birds, notably waterfowl, which eat them and void them later, perhaps in another habitat. Evidence for this comes from the finding of many small Tarebia granifera 5–7 mm in height and still containing the soft parts in unidentified bird droppings from the bank of the Mhlali River, South Africa. Even though the shell of Tarebia granifera is thick, most of these juveniles had been partially crushed with only a few still intact. Both the intact and damaged specimens could have been alive when passed and perhaps survived had they been deposited in water. None was large enough to have been reproductively mature (see below) and would have needed to survive in any new habitat for several months before reproducing.
Passive dispersal may also occur via weed on boats and boat trailers and via water pumped from one waterbody to another for industrial and irrigation purposes. In the Nseleni River juvenile Tarebia granifera were commonly found with another invasive snail, Pseudosuccinea columella, on floating clumps of water hyacinth Eichhornia crassipes which provide a vehicle for rapid downstream dispersal.
Once established in a particular waterbody Tarebia granifera is likely to disperse actively, both up and downstream in the case of flowing systems, as far as environmental factors like current speed and food availability will allow. The snail's tolerance of turbulent, flowing water was demonstrated by Prentice (1983). who reported it migrating upstream on the Caribbean island of Saint Lucia at a rate of 100 m month−1 in streams discharging up to 50 L.s−1. In KwaZulu-Natal it has been collected in water flowing at up to 1.2 m.s−1 which is likely to exceed the current speeds of at least the lower and middle reaches of many rivers and streams in South Africa making these watercourses open to colonization.
The sole of Tarebia granifera is proportionally small when compared to other thiarids and smaller snails with their higher coefficients were less able to grip the substratum in the face of moving water and so did not disperse as effectively as larger ones.
Density In Florida, Tucker Abbott (1952) recorded a density of Tarebia granifera 4444 m−2 which falls within the range of densities measured with a Van Veen grab in a number of sites in northern KwaZulu-Natal, where densities were measured from 843.6 ±320.2 m−2 to 20764.4 ±13828.1 m−2. The site with such high density was non-flowing, devoid of rooted vegetation but it was shaded by trees (Barringtonia racemosa) and by floating Eichhornia crassipes. This between-site variability may be positively correlated to habitat heterogeneity and food availability. Despite the high densities recorded in the Nseleni River, indigenous invertebrates were still present in the sediments including: bivalve Chambardia wahlbergi, chironomids, oligochaetes (tubificids) and burrowing polychaetes were also found but in low numbers.
The low densities of Tarebia granifera reported for the Mhlatuze River, South Africa may have been influenced by nearby sand mining activities or, more likely, high flows and mobile sediments, but they nevertheless approach those recorded by Dudgeon (1980)Dudgeon D. (1980). "The effects of water level fluctuations on a gastropod community in the rocky marginal zone of Plover Cove reservoir, Hong Kong". International Journal of Ecological and Environmental Sciences 8: 195–204. for Tarebia granifera in its native Hong Kong (18–193 m−2).