Pomacea canaliculata

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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. (Cowie, 2005)

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. (Cowie, 2005; Cowie, 2005)

  • Aquatic Biomes
  • lakes and ponds

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. (Ghesquiere, 2005a; Ghesquiere, 2005b; Tamburi and Martín, 2009)

  • Sexual Dimorphism
  • female larger
  • Range length
    40 to 60 mm
    1.57 to 2.36 in

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. (Ferguson, 2005; Ghesquiere, 2005a)

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. (Martin, 2002)

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. (Ferguson, 2005; Ghesquiere, 2005a)

  • Breeding interval
    Channeled apple snails breed more frequently in the spring and summer every few weeks and less frequently in the fall and winter.
  • Breeding season
    These snails breed all year but more in the summer and spring.
  • Average number of offspring
    200-600
  • Average gestation period
    1-2 weeks
  • Range time to independence
    15 to 25 days
  • Range age at sexual or reproductive maturity (female)
    45 to 59 days
  • Range age at sexual or reproductive maturity (male)
    45 to 59 days

There is no parental care by adult channeled apple snails after eggs are laid. (Yusa, 2006)

  • 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. ("Apple snails", 2011; Cowie, 2005)

  • Average lifespan
    Status: captivity
    4 years

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. (Cowie, 2005)

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. (Ghesquiere, 2005a)

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. (Ghesquiere, 2005a; Tamburi and Martín, 2009)

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. (Chan, et al., 2009)

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. (Ghesquiere, 2005b)

Commensal/Parasitic Species

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. (Ghesquiere, 2005a)

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. (Cowie, 2005)

  • Negative Impacts
  • crop pest

Conservation Status

This species has no conservation status.

Contributors

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

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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Neotropical

living in the southern part of the New World. In other words, Central and South America.

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agricultural

living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

biodegradation

helps break down and decompose dead plants and/or animals

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

detritivore

an animal that mainly eats decomposed plants and/or animals

detritus

particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

freshwater

mainly lives in water that is not salty.

herbivore

An animal that eats mainly plants or parts of plants.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

indeterminate growth

Animals with indeterminate growth continue to grow throughout their lives.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

macroalgae

seaweed. Algae that are large and photosynthetic.

marsh

marshes are wetland areas often dominated by grasses and reeds.

molluscivore

eats mollusks, members of Phylum Mollusca

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

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oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

phytoplankton

photosynthetic or plant constituent of plankton; mainly unicellular algae. (Compare to zooplankton.)

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

year-round breeding

breeding takes place throughout the year

zooplankton

animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)

References

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

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

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

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/#.