''Pomacea maculata'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of large

freshwater snail Freshwater snails are gastropod mollusks that live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs t ...

with an operculum, an

aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the family Ampullariidae, the apple snails. The

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

of its synonymous name ''Pomacea insularum'' is the island apple snail. Together with ''

Pomacea canaliculata ''Pomacea canaliculata'', commonly known as the golden apple snail or the channeled apple snail, is a species of large freshwater snail with gills and an operculum, an aquatic gastropod mollusc in the family Ampullariidae, the apple snails. S ...

'' it is the most

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

of the family Ampullariidae. It is considered as about the 58th worst alien species in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Distribution

The indigenous distribution of ''Pomacea maculata'' is South America. ''Pomacea maculata'' is reported from

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, and

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

and it probably occurs in

Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...

and

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

. The type locality is the

Río Paraná Rio or Río is the Portuguese and Spanish word for "river". The word also exists in Italian, but is largely obsolete and used in a poetical or literary context to mean "stream". Rio, RIO or Río may also refer to: Places United States * Rio, Fl ...

, which joins the

Río Uruguay The Uruguay River ( ; ) is a major river in South America. It flows from north to south and forms parts of the boundaries of Brazil, Argentina and Uruguay, separating some of the Argentine provinces of La Mesopotamia from the other two countr ...

just above

Buenos Aires Buenos Aires, controlled by the government of the Autonomous City of Buenos Aires, is the Capital city, capital and largest city of Argentina. It is located on the southwest of the Río de la Plata. Buenos Aires is classified as an Alpha− glob ...

, forming the

Río de la Plata The Río de la Plata (; ), also called the River Plate or La Plata River in English, is the estuary formed by the confluence of the Uruguay River and the Paraná River at Punta Gorda, Colonia, Punta Gorda. It empties into the Atlantic Ocean and ...

. The area between the Paraná and the Uruguay is the Argentine province of Entre Ríos, the southern part of which is marshy, with channels connecting the Paraná and the Uruguay.

Non-indigenous distribution

North America

Distribution of Pomacea maculata in the United States

The initial introductions in the United States were probably from aquarium release, aka "aquarium dumping", in Texas and Florida most likely in the early 1990s, but possibly as late as 2002. Since then, it has rapidly spread from its initial introduced populations in Texas and Florida, and ''Pomacea maculata'' has been documented throughout eight southeastern states as of 2013: *

American Canal The American Canal is an irrigation canal in the Upper Rio Grande Valley near El Paso, Texas. The canal acquires water from the Rio Grande from the American Diversion Dam at the Texas–New Mexico–Mexico border, northwest of downtown El P ...

and Mustang Bayou in Texas, * in 2006 in Verret Canal in Gretna, Louisiana. * Mississippi * Spring Hill Lake near Mobile, Alabama; * Alabaha River in Georgia; * Lake Munson, Lake Jackson, Lake Brantley, and many other locations in Florida; * South Carolina * North Carolina Established populations exist in Florida, Georgia, and Texas. In Florida, Georgia, and Texas, initially the occurrences of ''Pomacea maculata'' were incorrectly identified as ''

''. Subsequent

genetic testing Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...

confirmed that specimens collected in Florida, Georgia, and Texas were indeed ''Pomacea maculata''. Byers et al. (2013) predicted potential range of this species in the Southeastern United States. They indicated that the minimum temperature in the coldest months and maximum amount of precipitation in the warmest months are the best predictors.

Asia

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

, where golden apple snails were introduced in Asia, ''Pomacea maculata'' may be misidentified as ''

''. ''Pomacea maculata'' is also widespread in

Singapore Singapore, officially the Republic of Singapore, is an island country and city-state in Southeast Asia. The country's territory comprises one main island, 63 satellite islands and islets, and one outlying islet. It is about one degree ...

Description

This snail species was described by Georges Perry in March 1810. Perry also created the genus ''Pomacea'', and ''Pomacea maculata'' was described as the type of species. The snail can grow up to 15 centimeters (5.9 inches) in size. The eyes are just below the antennae. The colour of the shell varies from a pale olive green to a darker green, with dark bands across the shell. The shell is quite thin compared to other family members of the apple snail family. The inside has dark spots (maculata means spotted or stained). The shells of these applesnails are globular in shape. Normal coloration typically includes bands of brown, black, and yellowish-tan. Color patterns are however extremely variable, and both

albino Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and reddish pink or blue eyes. Individuals with the condition are referred to as albinos. Varied use and interpretation of ...

and gold color variations exist. The size of the shell is up to 150 mm (5.9 inches) in length. ''Pomacea maculata'' individuals can be difficult to differentiate morphologically from ''

'' (but egg masses are strikingly different to a trained observer). The color of the visible soft parts is grey-brown with dark spots.Stijn Ghesquiere
''Pomacea'' (''pomacea'') ''insularum''
The Apple Snail (Ampullariidae) Website http://www.applesnail.net, accessed 26 October 2008.

Ecology

Pomacea paludosa and Pomacea insularum eggs

Habitat

''Pomacea maculata'' commonly colonizes small water bodies, such as roadside ditches and littoral edges of larger water bodies. Experimentally determined incipient physiological tolerance limits under laboratory conditions for adult and juvenile ''Pomacea maculata'' collected in Texas are: * salinity: from 0.0 ‰ to 6.8-10.2 ‰ * pH: from 3.5-4.0 to 10.0-10.5 * temperature: 15.23 °C - 36.6 °C. It is also possible that the snails have behavioral mechanisms to tolerate low temperatures, such as burrowing, which could not be exhibited in laboratory experiments. * emersion: from 70 days at 30 °C (<5% relative humidity) to >308 days at 20-25 °C (>75% relative humidity)

Life cycle

This snail lays pink eggs in clutches above the water level. ''Pomacea maculata'' egg clutches contain 2000 eggs.

Feeding habits

''Pomacea maculata'' voraciously consumes aquatic vegetation. The snail’s extensive consumption of aquatic vegetation and ability to accumulate and transmit algal toxins through the

food web A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Position in the food web, or trophic level, is used in ecology to broadly classify organisms as autotrophs or he ...

heighten concerns about its spread. The snail eats dead and decaying plant matter and algae.

Impact

The limited ecological data on ''Pomacea maculata'' in the USA show that the species has considerable impacts, especially on native aquatic vegetation and snail species. In Florida, in particular, ''Pomacea maculata'' is much larger and more fecund than the native '' Pomacea paludosa'' (that produces 20–30 eggs). Recent laboratory studies have demonstrated that ''Pomacea maculata'' can transfer the

neurotoxin Neurotoxins are toxins that are destructive to nervous tissue, nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insult (medical), insultsSpencer 2000 that can adversely affect function ...

linked to

Avian Vacuolar Myelinopathy Avian vacuolar myelinopathy (AVM) is a fatal neurological disease that affects various waterbirds and raptors. It is most common in the bald eagle and American coot, and it is known in the killdeer, bufflehead, northern shoveler, American wigeon, ...

(AVM) to its avian predators. The invasion of ''Pomacea maculata'' has possibly affected the endangered snail kite, a specialist predator on the native ''Pomacea paludosa'', which seemingly experienced decreased foraging success and juvenile survival following invasion of ''Pomacea maculata''. There is a further, but largely unexplored risk that ''Pomacea maculata'' harbors rat lungworm parasite ''

Angiostrongylus cantonensis ''Angiostrongylus cantonensis'' is a nematode (roundworm) parasite that causes angiostrongyliasis, an infection that is the most common cause of eosinophilic meningitis in Southeast Asia and the Pacific Basin. The nematode commonly resides in the ...

''.

Human use

''Pomacea maculata'' is edible and part of the ornamental

pet trade Wildlife trade refers to the exchange of products derived from non-domesticated animals or plants usually extracted from their natural environment or raised under controlled conditions. It can involve the trade of living or dead individuals, tis ...

for freshwater aquaria.Ng, T. H., Tan, S. K., Wong, W. H., Meier, R., Chan, S. Y., Tan, H. H., & Yeo, D. C. (2016). "Molluscs for sale: assessment of freshwater gastropods and bivalves in the ornamental pet trade". ''PLoS ONE'' 11(8): e0161130.

References

This article incorporates a

public domain The public domain (PD) consists of all the creative work to which no Exclusive exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly Waiver, waived, or may be inapplicable. Because no one holds ...

work of the United States Government A work of the United States government is defined by the United States copyright law of the United States, copyright law, as "a work prepared by an officer or employee of the United States Government as part of that person's official duties".: ...

from the referenceBenson A. J. (2008). "''Pomacea insularum''".

USGS The United States Geological Survey (USGS), founded as the Geological Survey, is an government agency, agency of the United States Department of the Interior, U.S. Department of the Interior whose work spans the disciplines of biology, geograp ...

Nonindigenous Aquatic Species Database, Gainesville, FL.

Revision Date: 8/14/2007. and CC-BY-2.0 text from the reference CC-BY-2.5 text from the reference

External links

Non-native applesnails in Florida
��with map of distribution of ''Pomacea insularum'' in Florida.

on the University of Florida, UF / IFAS Featured Creatures Web site * http://www.applesnail.net/content/species/pomacea_maculata.htm * {{Taxonbar, from=Q62369 maculata Gastropods described in 1810