Pomacea canaliculata

Geographic Range

The channeled apple snail is native from Argentina to the Amazon basin. This species was also introduced to most of southern, eastern, and southeast Asia and the southern part of the United States.

• Biogeographic Regions
• nearctic nearctic
  • introduced introduced
• oriental oriental
  • introduced introduced
• neotropical neotropical
  • native native
• oceanic islands oceanic islands
  • introduced introduced

Habitat

The channeled apple snail is found in a variety of different habitats, including the subtropics and tropics in the Amazon Interior Basin and Plata Basin. This species is found in a variety of freshwater areas such as lakes, water courses, wetlands and agricultural areas. Temperature preferences for P. canaliculata range from 18 to 25 degrees C. Temperatures below 18 degrees or above 32 degrees C drastically increases the snail's mortality rate.

• Habitat Regions
• tropical tropical
• freshwater freshwater

• Aquatic Biomes
• lakes and ponds

• Wetlands
• marsh marsh
• swamp swamp

• Other Habitat Features
• agricultural agricultural

Physical Description

The shell of this snail is globular, from 40-60 mm high and 45-75 mm wide, but can reach 150 mm in length. These numbers vary depending on environmental conditions; the shell grows mostly in the spring and summer but growth slows in the fall and winter. The shell can be yellow, green or brown and has five to six whorls separated by a deep indented suture which gives it the “channeled” name. The aperture is large and oval shaped with males having a rounder aperture than females. However, females in the adult stage are overall larger than males. The operculum is moderately thick, corneous, concentric and light to dark brown in color. The operculum is retractable at the shell opening. The body of the snail can vary in color from yellow to brown and almost black. The siphon has yellow spots and its tentacles are curled under the shell when it is resting. The snail is closely related to other species in the canaliculata group, however, distinctions can be made by looking at the color of the eggs, shell size, angle of indented sutures and shell opening.

• Other Physical Features
• ectothermic ectothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female larger

Development

Pomacea canaliculata becomes sexually mature when 2.5 cm in diameter. Reproduction rates depend on environmental conditions and food availability. Reproduction is highest in the spring and summer and lowest in the fall and winter. Average clutch size is 200-600 eggs, laid every few weeks. Eggs are reddish in color and loosely attached to each other, and are attached to an object above surface. Eggs incubate from one to two weeks and after hatching, become juveniles in 15-25 days. The snails are sexually mature adults 45-59 days later. The reproductive period lasts from 2 months to 3 years; this period can decrease with latitude and environmental changes. Life cycles are shorter during good conditions when the snails remain reproductively active throughout the year. Life cycles are longer during tough conditions. When not reproducing because of harsh environmental conditions the channeled apple snails bury themselves in mud and decrease their metabolism while waiting for conditions to improve.

• Development - Life Cycle
• indeterminate growth indeterminate growth

Reproduction

Unlike most other snails, P. canaliculata is not hermaphroditic. A male and a female reproduce and if water conditions are optimal and food supply is adequate, they may mate. Due to the sexual dimorphism, these snails typically copulate in pairs. Copulation and spawning tend to be time-consuming activities. Intercourse can last 10-20 hours (and males fast during this time) while the egg-laying process can take up to five hours. In addition, males tend to choose larger females in order to produce more and healthier offspring.

Pomacea canaliculata becomes sexually mature when it reaches 2.5 cm in diameter. Reproductive rates depend on environmental conditions and food availability. Reproduction is highest in the spring and summer and lowest in the fall and winter. Average clutch size is 200-600 eggs, laid every few weeks (egg clutch sizes are 2.2-3.5 mm in diameter). The reproductive period lasts from 2 months to 3 years; this period can decrease with latitude and environmental changes. Life cycles are shorter during good conditions when the snails remain reproductively active throughout the year. Cycles are longer during tougher conditions.

• Key Reproductive Features
• iteroparous iteroparous
• year-round breeding year-round breeding
• sexual sexual
• fertilization fertilization
• oviparous oviparous

There is no parental care by adult channeled apple snails after eggs are laid.

• Parental Investment
• pre-fertilization
  • provisioning

Lifespan/Longevity

Pomacea canaliculata lives around four years, but will live longer at cooler temperatures. However, they cannot survive at temperatures less than 20 degrees C.

Behavior

Pomacea canaliculata is an amphibious animal. The snail leaves the water for land in search of fresh vegetation at night, and remains hidden near the surface of water during the day. While this species prefers higher temperatures around 25 degrees C, it is the more resistant to lower temperatures than other species in the genus Pomacea .

• Key Behaviors
• nocturnal nocturnal
• motile motile

Communication and Perception

Very little is known about communication between snails in this species, but it is thought that they release a chemical agent. Other snail species will communicate through chemical means.

• Communication Channels
• tactile tactile
• chemical chemical

• Perception Channels
• tactile tactile
• chemical chemical

Food Habits

Pomacea canaliculata eats microscopic vegetation, floating or submerged higher plants, detritus and dead insects. The channeled apple snail is also known for eating other freshwater snails. Younger snails of this species prefer algae and detritus, while older snails prefer higher plants. They are extremely polyphagous, meaning they feed on an extensive variety of foods. This is important because as their food availability and intake increases, they are more reproductively active.

• Primary Diet
• carnivore carnivore
  • molluscivore molluscivore
• herbivore herbivore
  • folivore folivore
  • algivore
  • eats sap or other plant foods
• omnivore omnivore
• detritivore detritivore

• Animal Foods
• mollusks
• zooplankton zooplankton

• Plant Foods
• leaves
• algae
• macroalgae macroalgae
• phytoplankton phytoplankton

• Other Foods
• detritus detritus

Predation

Solenopsis geminata , also known as the fire ant, is the only species known to specifically prey on the eggs of these snails. Egg clutches produced by this snail are extremely visible due to their bright colors on green vegetation. The distinguishing colors show unpalatability to predators. Experiments demonstrated the egg yoke makes it unpalatable to predators. Another defense against predation is depositing eggs on vegetation with thorns. Adults have a wide range of predators including insects, fish, amphibians, crocodilians, reptiles, crayfish, turtle, mammals and birds. Their main defense is dropping to the bottom and burying into a spot until they get into contact with a hard object like a stone.

Ecosystem Roles

These snails have been introduced to different areas by humans and quickly spread, particularly in wetlands. In wetlands and natural freshwater systems they compete with native snails for food and cause destruction of native aquatic vegetation. Their quick reproductive rate during high food availability causes them to rapidly change the habitat where they reside. Although the channeled apple snails have many predators, since they move mostly at night they are somewhat protected. Their eggs, however, are mainly preyed on by only one species, leading to high survival rates of the snails' offspring.

Pomacea canaliculata is an intermediate host for the rat lungworm, Angiostrongylus cantonensis , which is the most common cause of eosinophilic meningitis in Southeast Asia and the Pacific Basin.

• Ecosystem Impact
• biodegradation biodegradation

Economic Importance for Humans: Positive

Very little, if any, information is known about positive economic importance for humans from the channeled apple snail . However, they are cooked and eaten in parts of Asia such as China and Thailand. Their invasive nature has made their use in aquarium cultures a concern, and has been discouraged.

• Positive Impacts
• pet trade pet trade
• food food

Economic Importance for Humans: Negative

Pomacea canaliculata is one of the top 100 “World’s Worst Invaders.” Snails introduced in Asia have been the number one pest in rice fields, which leads to large economic losses in areas such as the Philippines. Snails introduced in Hawai’i became major taro pests. They can spread very quickly from agricultural areas to freshwater and other aquatic environments.

• Negative Impacts
• crop pest

Conservation Status

This species has no conservation status.

Additional Links

Encyclopedia of Life

Contributors

Erin Holswade (author), Rutgers University, Ananya Kondapalli (author), Rutgers University, David V. Howe (editor), Rutgers University, Renee Mulcrone (editor), Special Projects.

References

Chan, R., K. King-Lun, Q. Jian-Wen. 2009. The potential of the invasive snail Pomacea canaliculata as a predator of various life-stages of five species of freshwater snails. Malacologia , 51/2: 343-356. Accessed January 31, 2013 at http://www.bioone.org/doi/abs/10.4002/040.051.0208?prevSearch=Pomacea%2BCanaliculata&searchHistoryKey=&queryHash=1c3415bd381a0dd220bb119837fb0d92 .

Cowie, R. 2005. " Pomacea canaliculata " (On-line). Global invasive species database. Accessed January 31, 2013 at http://www.issg.org/database/species/ecology.asp?si=135 .

Ferguson, C. 2005. "The invasion of apple snails ( Pomacea canaliculata ) into Hawai'i: A case study in environmental problem solving" (On-line pdf). Accessed September 26, 2012 at http://www.ctahr.hawaii.edu/nrem/capstone/2005/applesnail2-last.pdf .

Ghesquiere, S. 2005. "Aquatic Invasive Species" (On-line). Accessed January 31, 2013 at http://www.in.gov/dnr/files/CHANNELED_APPLE_SNAIL.pdf .

Ghesquiere, S. 2005. "Apple Snails" (On-line). Accessed January 31, 2013 at www.applesnail.net .

Martin, P. 2002. Pomacea canaliculata (Gastropoda: Ampullariidae): Life-history traits and their plasticity. BioCell , 26/ 1: 83-89. Accessed January 31, 2013 at http://www.in.gov/dnr/files/CHANNELED_APPLE_SNAIL.pdf .

Tamburi, N., P. Martín. 2009. Feeding rates and food conversion efficiencies in the apple snail Pomacea canaliculata (Caenogastropoda: Ampullariidae). Malacologia , 51/2: 221-232. Accessed January 31, 2013 at http://www.bioone.org/doi/abs/10.4002/040.051.0201?prevSearch=pomacea%2Bcanaliculata%2Bfood&searchHistoryKey=&queryHash=309d18d4c6b3dbc0960fa39e069af19d .

Yusa, Y. 2006. Genetics of sex-ratio variation inferred from parent-offspring regressions and sib correlations in the apple snail Pomacea canaliculata . Heredity , 96/1: 100-105. Accessed January 31, 2013 at http://www.mendeley.com/research/genetics-of-sexratio-variation-inferred-from-parentoffspring-regressions-and-sib-correlations-in-the-apple-snail-pomacea-canaliculata/# .

2011. "Apple snails" (On-line). Accessed January 31, 2013 at http://www.aquariumfish.net/catalog_pages/misc_critters/snails.htm .