Channeled Apple Snail
Image of three Channeled Apple Snails (Photo from: www.bugwood.com Credit to: Jess Van Dyke)
- Large size, up to 10 cm
- More or less globular freshwater snails
- Shell color generally brownish or greenish, often with spiral banding patterns around the whorls
- Some aquarium bred snails are bright golden yellow
- Body color can vary from dark, almost black, to pale cream
- Presence is often first noted by observation of their bright pink egg masses laid on solid surfaces up to 50 cm above the water surface
- Eggs generally hatch between 7-15 days, depending on the temperature
- Clutches, reproductive output of the snails, occur every few weeks
- Clutches can reach to 1000 offsprings, but average between 200-300
- Live up to four years
- Become sexually mature anywhere from 3 months and 2 years, depending on temperature
The Channeled Apple Snail, Pomacea canaliculata, is a freshwater snail widely distributed in lakes, ponds and swamps throughout its native range of the Amazon Inferior Basin and the Plata Basin. This amphibious animal remains submerged during the day, hidden in vegetation near the surface. It is more active during the night, and leaves the water in search for fresh vegetation. The activity rate of this snail varies highly with the water temperature. At 18°C they hardly move around, in contrast with higher temperatures, e.g. 25°C. Nevertheless, the Channeled Apple Snail is more resistant to lower temperatures than most other snails from the genus Pomacea.
The Channeled Apple Snail has a voracious appetite for water plants including lotus, water chestnut, taro, and rice. This snail poses a serious threat to many wetlands around the world by the potential destruction of native aquatic vegetation that causes serious habitat modification, as well as competition with native fauna, including native snails.
Introduced widely from its native South America by the aquarium trade and as a source of human food, the Channeled Apple Snail is a major crop pest in south East Asia (primarily in rice) and Hawaii (taro). The Channeled Apple Snail was originally introduced from South America to south-east Asia around 1980 as a local food resource and as a potential gourmet export item, but the markets never developed. The snails either escaped or were released became a serious pest of rice throughout many countries of south-east Asia.
Climatic modeling has shown that the Channeled Apple Snail has the potential to spread to many, as of yet, uninfested parts of the world, for example the huge rice-growing areas of India. The Channeled Apple Snail has already been introduced to the USA and threatens the major rice-crops of Texas and California. Australia, in particular, is extremely concerned about its potential introduction to natural wetlands (e.g., Kakadu) as well as to rice-growing areas.
Channeled Apple Snails are introduced to new locations in various ways. They are imported for development of aquaculture projects for human food. They are possibly introduced as eggs or small juveniles attached to aquatic plants. They can also be developed as a domestic aquarium snail and sold in pet stores. Sometimes the snails are introduced illegally by smugglers, usually as a human food resource.
The most frequent local dispersal mechanism of Channeled Apple Snails is the escape (or even release) of these snails from aquaculture-facility confinement. Another method is the release of domestic aquarium snails. While the snails are in the water, currents become the leading means of dispersal within a watershed.
Portions of this article courtesy of: Global Invasive Species Database