|Scientific Name:||Melanoides tuberculata (Müller, 1774)|
Nerita tuberculata Müller, 1774
Thiara tuberculata (Mueller, 1774)
|Taxonomic Source(s):||Bouchet, P., Marshall, B. and Rosenberg, G. 2016. MolluscaBase (2015). World Register of Marine Species . Available at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=737544. (Accessed: 25 April 2016).|
|Taxonomic Notes:||The species name is sometimes spelled Melanoides tuberculatus (see Madhyastha 2012), but this is incorrect because Melanoides Olivier, 1804 was clearly intended to be feminine as it was combined with the feminine specific epithet fasciolata in the original description.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Van Damme, D. & Lange, C.|
|Contributor(s):||Neubert, E., Amr, Z.S.S. & Madhyastha, A.|
This species has a worldwide distribution with no specific threats affecting it and hence it is assessed as Least Concern.
|Previously published Red List assessments:|
|Range Description:||This species presently has a global distribution. Its original range covered subtropical and tropical Africa (with exception of most of coastal western Africa) and southern Asia. During the 20th century it was introduced, e.g. via rice cultivation, to many other regions and it is presently found over all of Africa, the entire Arabian Peninsula, western Asia, south and southeast Asia including southern China and also in Japan, Malaysia, Indonesia and Oceania (Liu et al. 1979, Brown 1994, Ramakrishna and Dey 2007). For the last two decades it has been moving northwards into Europe, having crossed the Mediterranean, and has been found for example in southern Spain (Álvarez Halcón 1995). It has also been introduced in North, Central and South America. In addition to the tropical-subtropical countries and regions listed, it also occurs in many Palaeartic countries indoors (aquariums, hothouses, garden shops) or outdoors in warm waters, either artificial ones such as cooling water ponds, e.g., of nuclear power plants or natural ones, such as a thermal spring outflow in Slovakia (Májsky 2000). On Madagascar it occurs over the whole island and is common in e.g., rice fields. The origin of the species in Madagascar (native or introduced) is uncertain. It also has been introduced in most islands in the Indian Ocean, including the Comoros, Mauritius, Mayotte, Réunion and the Seychelles.|
The distribution is kept actualized in the Invasive Species Compendium (http://www.cabi.org/isc/datasheetreport/75617).
Native:Bangladesh; Benin; Brunei Darussalam; Burundi; China; Congo; Congo, The Democratic Republic of the; Egypt; Eritrea; Ethiopia; Gabon; India; Kenya; Lao People's Democratic Republic; Libya; Malawi; Malaysia; Mauritania; Mozambique; Namibia; Niger; South Africa; South Sudan; Sri Lanka; Sudan; Swaziland; Tanzania, United Republic of; Thailand; Timor-Leste; Uganda; Viet Nam; Yemen (North Yemen, Socotra, South Yemen); Zimbabwe
Introduced:Algeria; Australia; Bahrain; Bolivia, Plurinational States of; Brazil; Comoros; Cuba; Dominica; Ecuador (Ecuador (mainland)); Fiji; French Guiana; French Polynesia; Germany; Guadeloupe; Guyana; Honduras; Japan; Kuwait; Malta; Martinique; Mauritius (Mauritius (main island)); Mayotte; Montserrat; Nepal; Netherlands; New Caledonia; New Zealand; Panama; Papua New Guinea; Paraguay; Puerto Rico; Réunion; Saint Lucia; Samoa; Seychelles (Seychelles (main island group)); Slovakia; Spain (Spain (mainland)); Suriname; Tonga; Trinidad and Tobago; United States; Uruguay; Venezuela, Bolivarian Republic of; Wallis and Futuna
Present - origin uncertain:Madagascar; Morocco; Oman; Qatar; Saudi Arabia; Tunisia; United Arab Emirates
|Range Map:||Click here to open the map viewer and explore range.|
Subpopulations may reach extremely high densities of 200-300 ind/m² in Lake Chad (Lévêque 1967) and up to 10,000 ind/m² (Pererea and Walls 1996) in sandy or gravelly sediments where the snails do not only live upon the surface but also in the top-layer (endobenthic). In Lake Victoria M. tuberculata is the most abundant gastropod. Ngupula and Kayanda (2010) cite an average density of 250 ind/m² in the littoral zone of the Tanzanian sector.
|Current Population Trend:||Increasing|
|Habitat and Ecology:||This species is found in all types of permanent waters, from small springs to vast lakes, e.g. Lake Victoria, and from oligotrophic to eutrophic waters. In Madagascar, it is also found in rice paddies. It is a browser of microalgae and a detritivore, feeding on detritus, plant leaves and dead animals, and is able to survive in relatively alkaline and saline waters. This species is parthenogenetic and is spread by birds. This species is the intermediate host of several trematodes.|
|Continuing decline in area, extent and/or quality of habitat:||Unknown|
|Congregatory:||Congregatory (and dispersive)|
|Use and Trade:||This species has been spread worldwide, for example via the aquarium trade and rice cultivation. It is well known that this species is eaten by molluscivorous fish, such as some cichlid species and carp, but its use as a commercially interesting food source in fish farming requires confirmation. It is sometimes used in ethnic ornaments.|
|Major Threat(s):||This species can even thrive in aquatic habitats strongly impacted by human activities e.g. eutrophied artificial lakes, rice paddies, canals, etc. It seems resistant to most threats, severe droughts excepted.|
Considering the strongly invasive nature of this opportunistic species that presently is circumtropical and is moving north in the temperate zone (due to climate change), it constitutes a threat to aquatic biodiversity. No conservation actions are needed for this species.
|Amended reason:||Point locality records for this species were recently compiled by D. Van Damme and these are now displayed on the distribution map.|
|Citation:||Van Damme, D. & Lange, C. 2017. Melanoides tuberculata (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2017: e.T155675A110779677.Downloaded on 24 June 2018.|
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