Pomacea
| Pomacea | ||||||||||||
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Pink form of Pomacea diffusa |
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| Scientific name | ||||||||||||
| Pomacea | ||||||||||||
| Perry , 1810 |
Pomacea is a genus of the apple snail family(Ampullariidae). The species of this genus are distributed in the southern USA, in Central and South America. There are96 species ofthe genus Pomacea , including fossil taxa . There are 89 species still alive today.
Etymology and history of research
The first description of the genus and its type species Pomacea maculata was made in 1810 by the British architect, stonemason and naturalist George Perry in his own journal Arcana - or the Museum of Natural History . The generic name chosen by Perry is derived from the Latin pomum 'apple' and refers to the special shape of the snail shell .
features
Apple snails are large freshwater snails that are native to the tropics and subtropics of America, Africa, and Asia. Some species in the genus Pomacea are among the largest freshwater snails in the world. All apple snails have a housing lid and a pair of lip buttons to the right and left of the mouth in addition to the long antennae that sit above the eyes.
Characteristic of the apple snails of the genus Pomacea are a right-hand twisted shell, a horny shell lid, a long siphon that is formed into a closed tube when breathing, and clutches of chalky eggs that are deposited above the surface of the water.
The largest species are Pomacea canaliculata and Pomacea urceus , whose bodies can reach more than 12 cm in diameter.
Ecology and biology
The Pomacea species live in wetlands (e.g. Everglades in Florida) and on rivers (e.g. Amazon region). They breathe in air on the surface of the water and can thus survive in oxygen-poor waters. The animals survive dry times by digging into the ground for a resting phase. In doing so, they change their metabolism and sometimes lose a lot of body mass.
Apple snails are separate sexes and reproduce by mating between males and females. In nature the gender ratio is balanced. When mating, the males hold on to the housing of the female and transfer sperm into the female sexual opening. The eggs are fertilized in the female's body. They are then deposited by the female above the water.
The eggs of Pomacea canaliculata , Pomacea insularum, and Pomacea maculata are red. The clutches of Pomacea glauca are green. For most of the other species, the eggs are beige, cream, or white. The clutch comprises between 50 and 1000 eggs. The young hatch after about 2 to 3 weeks. The viviparous Pomacea urceus is an exception . It lays its eggs in its own housing and burrows itself with the clutch during the rest period. The young animals hatch under the housing.
- Clutch of various apple snails
Clutches of Pomacea paludosa (top left) and Pomacea insularum (bottom right)
Clutches of Pomacea diffusa
Clutches of Pomacea canaliculata
Clutch of Pomacea haustrum
Importance to humans
Some large pomacea species have been brought from South America to Asia as food, where they cause severe damage to taro and rice . In areas where Pomacea species continue to spread, native apple snails (e.g. Pila scutata ) are being pushed back.
Eating raw or not fully cooked apple snails can transmit parasites to humans. One of these parasites is the rat lungworm ( Angiostrongylus cantonensis ). Man is a false host for worms. It enters the brain and causes inflammation of the brain and meninges ( meningoencephalitis ). This special form of encephalitis is also called angiostrongyliasis because of the pathogen. A Chinese study found that six out of seven outbreaks of this zoonosis between 1997 and 2006 in China were due to the consumption of infected Pomacea canaliculata .
Apple snails of the genus Pomacea are popular invertebrates in the aquarium hobby . They have been known as aquarium animals since the beginning of the 20th century. The pointed apple snail ( Pomacea diffusa ) in particular is widespread because it is the only known Pomacea species that does not eat any living plants and can therefore be kept in a normal community aquarium. There are cultivated forms of the kind with yellow, white, brown and pink colored houses and white or blue-black bodies.
Since January 1, 2013, the import of all types of pomacea into the EU as well as the trade, transfer and reproduction of the animals in the EU has been prohibited. The reason is the introduction of herbivorous Pomacea species to Spain. There, the animals damage rare native plants in the already endangered swamp areas.
literature
- G. Perera, JG Walls (1996): Apple Snails in the Aquarium . - 2nd edition, TFH Publications, Inc., USA
- M. Wilstermann-Hildebrand (2009): Apple snails - The family of the Ampullariidae . Art for Art, Natur- und Tier-Verlag, Münster
Individual evidence
- ^ KA Hayes, RL Burks, A. Castro-Vazquez, Ph. C. Darby, H. Heras, PR Martín, J.-W. Qiu, SC Thiengo, IA Vega, T. Wada, Y. Yusa, S. Burela, M. Pilar Cadierno, JA Cueto, FA Dellagnola, MS Dreon, MV Frassa, M. Giraud-Billoud, MS Godoy, S. Ituarte, E. Koch, K. Matsukura, MY Pasquevich, C. Rodriguez, L. Saveanu, ME Seuffert, EE Strong, J. Sun, NE Tamburi, MJ Tiecher, RL Turner, PL Valentine-Darby, & RH Cowie: Insights from an Integrated View of the biology of Apple Snails (Caenogastropoda: Ampullariidae) . In: Malacologia , Volume 58, Numbers 1-2, 2015, S, 245-302. ( Digitized version ).
- ↑ RH Cowie: The recent apple snails of Africa and Asia (Mollusca: Gastropoda: Ampullariidae: Afropomus, Forbesopomus, Lanistes, Pila, Saulea): a nomenclatural and type catalog. The apple snails of the Americas: addenda and corrigenda. In: Zootaxa - Monograph , Volume 3940, 2015, pp. 1–92, ( digitized version ).
- ↑ a b G. Perry: Pomacea maculata. In: Arcana - or the Museum of Natural History , 1810, unnumbered, ( digitized version ).
- ^ RE Petit: Perry's Arcana: A Facsimile Edition with a Collation and Explanatory Essay. Temple University Press, Philadelphia, 2009, ISBN 978-1-4399-0195-3 , pp. Vii, ( preview ).
- ^ Ph. C. Darby, PL Valentine-Darby & HF Percival: Dry season survival in a Florida apple snail (Pomacea paludosa Say) population. In: Malacologia , Volume 45, Number 1, 2003, pp. 179-184, ( digitized version ).
- ↑ IW Ramnarine: Induction of spawning and artificial incubation of eggs in the edible snail Pomacea urceus (Muller). In: Aquaculture , Volume 215, Numbers 1-4, 2003, pp 163-166, ( abstract ).
- ↑ BO Acosta & RSV Pullin (Eds.): Environmental Impact of the Golden Apple Snail (Pomacea sp.) On Rice Farming Systems in the Philippines. Summary Report of the Workshop held at the Freshwater Aquakulture Center, Central Luzon State University Nueva Ecija, Philippines November 9-11, 1989, Manila, 1991, ISBN 971-10-2291-5 . P. 34, ( Preview ).
- ^ RH Cowie: Apple Snails (Ampullariidae) as Crop Pests: Their Biology, Impacts and Management. In: GM Barker (Ed.): Molluscs as Crop Pests , CABI Publishing, 2002, ISBN 0-85199-320-6 , pp. 145-192 ( preview ).
- ↑ R. & Th Chaichanaa Sumpana. The potential ecological impact of the exotic snail Pomacea canaliculata on the Thai native snail Pila scutata. In: ScienceAsia , Volume 40, 2014, pp. 11–15, ( digitized version ).
- ↑ S. Lv, Y. Zhang, P. Steinmann & X.-N. Zhou: Emerging Angiostrongyliasis in Mainland China. In: Emerging Infectious Diseases , Volume 14, Number 1, 2008, pp. 161–164, ( digitized version )
- ↑ M. Wilstermann-Hildebrand: Apple snails - The family of the Ampullariidae. Natur und Tier Verlag, Münster, 2009, ISBN 978-3-86659-128-8 , 64 pp.
- ↑ M. Šefčovič: Implementing decision of the Commission of November 8, 2012 regarding measures to protect against the introduction of the genus Pomacea (Perry) into the EU and its spread in the EU. In: Official Journal of the European Union . Case number C (2012) 7803, 2012.