Origin: South America
Impact: Apple snails (Pomacea maculata) can grow to up to six inches high -- about the size of a baseball or human fist -- although a size of approximately 1.5 inches is more common. Their presence is often first detected by observation of their bright pink egg masses, which are laid just above the water line on emergent vegetation, woody debris, and manmade structures.
Negative ecological effects of this invasive snail species include habitat degradation and competition with native snails. Apple snails are voracious herbivores and feed on a wide variety of both native and introduced submerged, floating, and emergent aquatic plants. They reproduce prolifically and can attain high population density, decimating the aquatic vegetation. In addition to their harmful effects on existing habitat, herbivory by these snails can threaten the success of wetland restoration efforts.
Invasive apple snails cause significant damage to rice crops in Asia and potential for similar economic impacts in Texas is a major concern. Although damage to rice crops in Texas has not yet been documented, some rice farmers have experienced increased levee maintenance costs due to the constant burrowing by snails.
Apple snails also pose a risk to human health as they are an intermediate host to the rat lungworm, Angiostrongylus cantonesis, a parasite that can infect mammals, including humans. Humans can become infected by this parasite by eating raw or undercooked snails or by eating raw produce contaminated by rat lungworm larvae. Humans with mild infections usually recover fully. However, severe infections of the parasite can cause eosinophilic meningitis. Rat lungworm has been found in apple snails collected from New Orleans, Louisiana.
Learn More: Species Profile.
If you have spotted Pomacea maculata (Apple Snail), use this report form to send an email to the appropriate authorities.