Island Apple Snail

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. The shells average 5 - 6 whorls and coil dextrally. The size of the shell is up to 150 mm (5.9 inches) in length. Normal coloration typically includes bands of brown, black, and yellowish-tan. Shells also tend to have a yellow to reddish orange coloring along the lip of the large opening. Color patterns are however extremely variable, and both albino and gold color variations exist. The operculum of Pomacea maculata is dark brown in color and can be used to differentiate male and female snails. A female Pomacea maculata will have an operculum with uniform concavity, while the operculum in males has uneven concavity. Pomacea maculata individuals can be difficult to differentiate morphologically from Pomacea canaliculata (but egg masses are strikingly different to a trained observer). …

The indigenous distribution of Pomacea maculata is South America. Pomacea maculata is reported from Argentina, Brazil, and Bolivia and it probably occurs in Uruguay and Paraguay. The type locality is the Río Paraná, which joins the Río Uruguay just above Buenos Aires, forming the Río de la Plata. 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.

North America. 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 at least 10 different states as of 2024:

American Canal and Mustang Bayou in Fort Bend County and Brazoria County, Texas, in 2006 in Verret Canal in Gretna, Louisiana. The Pascagoula and Pearl River, Mississippi Spring Hill Lake near Mobile, Alabama; Alabaha River in Georgia; Lake Munson, Lake Jackson, Lake Brantley, and many other locations in Florida; Waccamaw River, Cooper River, and Lake Marion, South Carolina Lumber River, North Carolina In October 2019 on the San Antonio Riverwalk, San Antonio, Texas Agua Fria and the Salt River, Arizona Eastern and southern …

Pomacea maculata displays sexual dimorphism, females tend to be larger than males. The females are capable of producing a full clutch of eggs within their first year of life. Pomacea maculata reproduces sexually and eggs are internally fertilized. Females can store sperm meaning that multiple clutches can result from one mating event. This snail lays pink eggs in clutches above the water level. Pomacea maculata egg clutches contain anywhere between 1500-2100 eggs. One individual can lay up to 56,000 eggs over its lifespan. The eggs are a very saturated bight pink when first laid. Over time, while they dry out they become ashy which makes them a less saturated color. As the eggs hatch they turn white. These eggs are laid just above the waterline on vegetation or rocky surfaces. Prolonged submergence in water can damage the eggs and cause them to die. Once the eggs are laid, it typically takes 10-14 days for the entire clutch to hatch.