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
- oriental
- neotropical
- oceanic islands
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
- freshwater
- Aquatic Biomes
- lakes and ponds
- Other Habitat Features
- 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
- heterothermic
- 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
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
- year-round breeding
- sexual
- fertilization
- 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
.
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.
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
-
herbivore
- folivore
- algivore
- eats sap or other plant foods
- omnivore
- detritivore
- Animal Foods
- mollusks
- zooplankton
- Plant Foods
- leaves
- algae
- macroalgae
- phytoplankton
- Other Foods
- 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
- Rat lungworm, Angiostrongylus cantonensis
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.
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
Contributors
Erin Holswade (author), Rutgers University, Ananya Kondapalli (author), Rutgers University, David V. Howe (editor), Rutgers University, Renee Mulcrone (editor), Special Projects.
- 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.
- introduced
-
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
- oriental
-
found in the oriental region of the world. In other words, India and southeast Asia.
- introduced
-
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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.
- introduced
-
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- freshwater
-
mainly lives in water that is not salty.
- marsh
-
marshes are wetland areas often dominated by grasses and reeds.
- swamp
-
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
- agricultural
-
living in landscapes dominated by human agriculture.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- 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.
- 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.
- indeterminate growth
-
Animals with indeterminate growth continue to grow throughout their lives.
- 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).
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- zooplankton
-
animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)
- macroalgae
-
seaweed. Algae that are large and photosynthetic.
- phytoplankton
-
photosynthetic or plant constituent of plankton; mainly unicellular algae. (Compare to zooplankton.)
- detritus
-
particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).
- biodegradation
-
helps break down and decompose dead plants and/or animals
- pet trade
-
the business of buying and selling animals for people to keep in their homes as pets.
- food
-
A substance that provides both nutrients and energy to a living thing.
- carnivore
-
an animal that mainly eats meat
- molluscivore
-
eats mollusks, members of Phylum Mollusca
- herbivore
-
An animal that eats mainly plants or parts of plants.
- folivore
-
an animal that mainly eats leaves.
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
- detritivore
-
an animal that mainly eats decomposed plants and/or animals
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. MartĂn. 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 .