CHANNELED APPLE SNAILS
Dana Denson, Aquatic Biologist
FL Department of Environmental Protection
(407) 894-7555, ext. 2355
Photo courtesy of Katasha Cornwell, FDOT.
Populations of the channeled apple
snail (Pomacea canaliculata), a
larger relative of the native
of channeled apple snails have been reported in
lay masses of 100-1200 bright pink eggs an average of
1.4 times per week on any type of firm substrate available about 6 to 8 inches
above the water line. Egg-laying continues year-round in central and south
In tests, they have been shown to consume almost every submersed aquatic plant species offered. Unfortunately, they do not appear to prefer hydrilla, but are more fond of plants like southern naiad, red ludwigia, Cabomba, and bladderworts. Young snails may become reproductive as early as 2 to 3 months of age.
Like native Pomacea, channeled apple snails possess both a lung and a gill, as well as a snorkel-like siphon through which they can breathe atmospheric air, at the same time reducing the risk of attack by terrestrial predators. They can resist dessication by closing their shells using their opercula, as well as by estivating in sediments for up to 5 months. They can tolerate salinity to 8 parts per thousand, and seem unaffected by nutrient enrichment and low oxygen levels.
In Florida, populations are now reported in all central Florida counties, most south Florida counties, and Leon County in the panhandle (see map). It is likely that they will spread to many other areas, and perhaps throughout the state.
effective control measures have yet been found. The use of molluscicides
would be expensive, and would likely have significant negative effects on
non-target organisms. Although there are predators which feed on channeled apple
snails (snail kites, large herons, large turtles, probably alligators, and most
notably, limpkins), the relative abundance of these predators is eclipsed by
the huge populations of channeled apple snails that have been seen in many
locations. The use of water-level manipulations to drown eggs in controlled
situations would probably help in reducing egg densities somewhat, but at a
rate of one clutch laid every 4 or 5 days, the impact to snail populations
would probably be limited. Physical removal projects have been carried out in
If you find these channeled apple snails and/or their eggs, please contact Dana Denson, Aquatic Biologist, Florida Department of Environmental Protection, at email@example.com, or call (407) 894-7555, ext. 2355.
FOR MORE INFORMATION:
· Carlsson, N. et al. 2004. Invading herbivory: the golden apple snail alters ecosystem functioning in Asian wetlands. Ecology 85(6):1575-1590.
· Cowie, R.H. 2004. Ecology of Pomacea canaliculata. Global Invasive Species Database. http://www.issg.org/database/species/ecology.asp?si=135&fr=1&sts=
· Florida Department of Environmental Protection, Central District website: http://www.dep.state.fl.us/central/Home/Watershed/Snails.htm
· Ghesquiere, S. 2003. The apple snail website. http://www.apple snail.net/content/species/pomacea_canaliculata.htm
2003. Pomacea canaliculata: Channeled
apple snail releases threaten
· Howells, R.G. and J.W. Smith. Status of the apple snail Pomacea canaliculata in the United States, report to The Seventh International Congress on Medical and Applied Malacology (7th ICMAM), Los Baños, Laguna, Philippines
2002. Introduced Species Summary project,
2000. "Pilidae" (On-line), Animal Diversity Web. Accessed