Giant African snails
| Giant African snails | ||||||||||||
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Giant African snail |
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| Swainson , 1840 |
The African giant snails (Achatinidae), also called large agate snails , are a family of land snails . Although there are numerous smaller species among the African giant snails, the genus Achatina contains the largest terrestrial snails on earth. The largest representative of the African giant snail is the real agate snail ( Achatina achatina ), which can reach a shell length of up to 20 cm (measured from the apex to the shell mouth). The shell itself is conical and tapering to a point, while the body often resembles that of the Roman snail known in Europe .
In Europe there is a family of very small land snails, which are also called "agate snails" (or also smooth snails ), but are not closely related to the giant African snails.
distribution
The natural range of the family is limited to sub-Saharan Africa. The limit of distribution in the north extends from Senegal in the west over the Lake Chad region to southern Ethiopia and Somaliland in the east. In the south they reach the south coast of the Cape Province in South Africa. The number of species is highest in central Africa, both in the east and in the west, while both South Africa and the northeast are poorer in species. The islands of São Tomé and Príncipe have few ( endemic ) species.
The great agate snail, Lissachatina fulica , in particular , was brought to a number of regions with a similar climate and is now an invasive species almost worldwide.
Biology and ecology
Species of the family live mainly in forests such as the tropical rainforest, but also occur in drier, savannah-like habitats. Few species (with relatively small body size) penetrate into desert-like habitats in the south. Many species tolerate clearing in the forest, they occur in hardly reduced density in plantations and in cultivated land, where they can occasionally be harmful to cultivated plants. In indigenous habitats, however, the species never achieve such high densities as the great agate snail in some regions into which it has been introduced. Many of the larger species are intensively gathered as meat suppliers.
Due to their sensitivity to drought, almost all species are strictly nocturnal. When dry, many species can seal their housing with a diaphragm.
The snails feed on both vegetable and animal food. In the wild they feed on almost every imaginable plant species, from fruits, bark and carrion. Accordingly, when kept in the terrarium, they can be supplied with all kinds of fruit and vegetables , but also with beef and cat food. Banana peels are also a good source of nutrition. Since the African giant snails have large shells that are thick and heavy, they need a lot of lime to build them . They take in most of this lime through their food. Calcareous earth is absorbed as well as calcareous rock . When keeping pets, we recommend adding sepia shells as a source of lime.
Reproduction
African giant snails are hermaphroditic (hermaphroditic), that is, they have both male and female sexual organs . During mating, semen is exchanged, then the egg cells develop and the animals fertilize them with the stored semen. This means that a clutch does not have to occur immediately after copulation . Most members of the Achatinidae family lay eggs that are either small and numerous (often over 300 eggs per clutch) or quite large but few. Some species such as Achatina iredalei are even viviparous . Usually, the giant African snails lay their eggs in a self-dug cave in the moist soil. This usually happens in a place where the soil is as calcareous as possible. The reason for this is that the juvenile snails spend the first part of their life in the ground, where they take in lime and food to strengthen their fragile little shells. If the ground is too wet, embryos and young snails can suffocate. If the young are strong enough, they hit the surface. You are completely independent.
Genera
The different genera of the Achatinidae family differ in size, shape and color of the housing and the soft body. The two best-known genera are Achatina and Archachatina . The distinguishing feature of these two genera is the size of the eggs, the columella and the ending of the apex . Species of the Achatina genus lay eggs that are approx. 5 mm in size , but up to 300 eggs , whereas Archachatina species only lay a few eggs that are approx. 2 cm in size.
The following list of the genera follows the database MolluscaBase
- Subfamily Achatininae Swainson, 1840
- Tribe Achatinini Swainson, 1840
- Genus Achatina Lamarck, 1799
- Genus Archachatina Albers, 1850
- Genus Atopocochlis Crosse & P. Fischer, 1888
- Genus Bequaertina Mead, 1994
- Genus Brownisca Mead, 2004
- Genus Bruggenina Mead, 2004
- Genus Burtoa Bourguignat, 1890
- Genus Cochlitoma A. Férussac, 1821
- Genus Leptocalina Bequaert, 1950
- Genus Leptocallista Pilsbry, 1904
- Genus Lignus Gray, 1834
- Genus Lissachatina Bequaert, 1950
- Genus Metachatina Pilsbry, 1904
- Genus Pseudachatina Albers, 1850
- Tribus Callistoplepini Mead, 1994
- Genus Callistoplepa Ancey, 1888
- Genus Leptocala Ancey, 1888
- Tribe Limicolariini Schileyko, 1999
- Genus Columna Perry, 1811
- Genus Limicolaria Schumacher, 1817
- Genus Limicolariopsis d'Ailly, 1910
- Tribe Achatinini Swainson, 1840
- Subfamily Coeliaxinae Pilsbry, 1907
- Genus Balfouria Crosse, 1885
- Genus Coeliaxis H. Adams & Angas, 1865
- Genus Ischnocion Pilsbry, 1907
- Genus Nannobeliscus Weyrauch, 1967
- Genus Neosubulina EA Smith, 1898
- Genus Riebeckia E. von Martens, 1883
- Subfamily Cryptelasminae Germain, 1916
- Genus Cryptelasmus Pilsbry, 1907
- Genus Thomea Girard, 1893
- Glessulinae Godwin-Austin subfamily, 1920
- Genus Glessula E. von Martens, 1860
- Subfamily Opeatinae Thiele, 1931
- Genus Eremopeas Pilsbry, 1906
- Genus Opeas Albers, 1850
- Subfamily Petriolinae Schileyko, 1999
- Genus Aporachis D. Holyoak, 2020
- Genus Bocageia Girard, 1893
- Genus Ceras Dupuis & Putzeys, 1901
- Genus Chilonopsis Fischer von Waldheim, 1848
- Genus Cleostyla Dall, 1896
- Genus Comoropeas Pilsbry, 1906
- Genus Dictyoglessula Pilsbry, 1919
- Genus Homorus Albers, 1850
- Genus Ischnoglessula Pilsbry, 1919
- Genus Itiopiana Preston, 1910
- Genus Kempioconcha Preston, 1913
- Genus Liobocageia Pilsbry, 1919
- Genus Mabilliella Ancey, 1886
- Genus Nothapalinus Connolly, 1923
- Genus Nothapalus E. von Martens, 1897
- Genus Oleata Ortiz de Zárate & Ortiz de Zárate, 1959
- Genus Oreohomorus Pilsbry, 1919
- Genus Petriola Dall, 1905
- Genus Subuliniscus Pilsbry, 1919
- Genus Subulona E. von Martens, 1889
- Subfamily Pyrgininae Germain, 1916
- Genus Pseudobalea Shuttleworth, 1854
- Genus Pyrgina Greef, 1882
- Subfamily Rishetiinae Schileyko, 1999
- Genus Bacillum Theobald, 1870
- Genus Eutomopeas Pilsbry, 1946
- Genus Rishetia Godwin-Austen, 1920
- Genus Tortaxis Pilsbry, 1906
- Subfamily Rumininae Wenz, 1923
- Genus Krapfiella Preston, 1911
- Genus Lubricetta F. Haas, 1928
- Genus Namibiella Zilch, 1954
- Genus Rumina Risso, 1826
- Genus Xerocerastus Kobelt & Möllendorff, 1902
- Subfamily Stenogyrinae P. Fischer & Crosse, 1877
- Genus Chryserpes Pilsbry, 1906
- Genus Cupulella Aguayo & Jaume, 1948
- Genus Dolicholestes Pilsbry, 1906
- Genus Lyobasis Pilsbry, 1903
- Genus Neobeliscus Pilsbry, 1896
- Genus Obeliscus H. Beck, 1837
- Genus Ochroderma Ancey, 1885
- Genus Ochrodermatina Thiele, 1931
- Genus Ochrodermella Pilsbry, 1907
- Plicaxis Sykes genus , 1903
- Genus Promoussonius Pilsbry, 1906
- Genus Protobeliscus Pilsbry, 1906
- Genus Rhodea H. Adams & A. Adams, 1855
- Genus Stenogyra Shuttleworth, 1854
- Genus Synapterpes Pilsbry, 1896
- Genus Zoniferella Pilsbry, 1906
- Subfamily Subulininae P. Fischer & Crosse, 1877
- Genus Allopeas HB Baker, 1935
- Genus Beckianum HB Baker, 1961
- Genus Curvella Chaper, 1885
- Genus Dysopeas HB Baker, 1927
- Genus Euonyma Melvill & Ponsonby, 1896
- Genus Fortuna Schlickum & Strauch, 1972
- Genus Hypolysia Melvill & Ponsonby, 1901
- Lamellaxis genus Strebel & Pfeffer, 1882
- Genus Lavajatus Simone, 2018
- Genus Leptinaria H. Beck, 1837
- Genus Leptopeas HB Baker, 1927
- Genus Micropeas Connolly, 1923
- Genus Neoglessula Pilsbry, 1909
- Genus Paropeas Pilsbry, 1906
- Genus Pelatrinia Pilsbry, 1907
- Genus Prosopeas Mörch, 1876
- Genus Pseudoglessula O. Boettger, 1892
- Genus Pseudopeas Putzeys, 1899
- Genus Striosubulina Thiele, 1933
- Genus Subulina H. Beck, 1837
- Genus Vegrandinia Salvador, Cunha & Simone, 2013
- Genus Zootecus Westerlund, 1887
- Subfamily Thyrophorellinae Girard, 1895
- Genus Thyrophorella Greeff, 1882
Selected species in the terrarium
The following species are often kept in terrariums:
Lissachatina fulica
The large agate snail reaches a length of up to 13 cm. The basic color of the housing is dark brown to horn-colored and has numerous stripes. The soft body is light to dark brown and has an eel line. A clutch can contain up to 300 eggs. The apex is pointed and white to red. Lissachatina fulica is the most common species in terrarium keeping.
Lissachatina fulica rodatzi
Lissachatina fulica rodatzi is a subspecies of the Lissachatina fulica , but due to countless matings in the terrarium hobby , the typical characteristics for this subspecies have almost disappeared. Initially, this subspecies had a much more bulbous shell, which made it different from the Achatina fulica subspecies. The special thing about the Lissachatina fulica rodatzi is the part of albinism that affects the housing. Due to the lack of color pigments, the shell appears yellow to horn-colored and streak-free. The body, on the other hand, is quite normal gray to brownish in color. Lissachatina fulica rodatzi reaches a casing length of about 10–12 cm. The apex is pointed, the columella is gray to colorless. Albinotic forms of this subspecies are also kept in terrariums.
Lissachatina allisa
With a shell size of approx. 7 cm, it is a relatively small giant snail species. The housing is light yellow with yellow stripes to white, the soft body is white to yellowish. The apex is pointed. The peculiarity of this species is that it is one of the few African giant snails that gives birth to living young instead of laying eggs. The clutch size is limited to about 30 young animals, which are also larger than the eggs in the clutches of the other Achatina species, since they are already fully developed.
Achatina achatina
The real agate snail is the largest land snail known to date and can reach a length of up to 20 cm. The basic color varies between very light, almost yellow and a dark brown. A brown to black stripe pattern can be seen on it, which has also given the species the name "tiger". The body itself is usually very dark, colored light gray to black. On the rear end of the soft body there is a kind of "V", formed by raised parts of the soft body (looks like a horn-like attachment). The apex is pointed and the columella is red.
Lissachatina reticulata
is the second largest land snail and can reach a shell length of 18 cm. The basic color of the housing is white to cream / beige and has various stain patterns in dark to light brown shades. The soft body is beige with a dark brown to black head and eye stalks, but there are also body albinos with completely white / yellowish soft bodies , which are often very popular with snail keepers and breeders. The apex is pointed and the housing has a grooved, fluted surface.
Lissachatina immaculata
are available in three color variants.
Achatina immaculata immaculata has a largely uniform coloring of the last turn of the casing. This varies from light to dark brown. The previous turns are lighter.
Achatina immaculata panthera has a golden to brown basic color of the house with a distinct stripe pattern.
Achatina immaculata "two-tone" has a lengthwise split color of the last house turn. This can vary between pink and purple. The basic color is white to golden-brown.
All three variants of the Lissachatina immaculata have a white apex and the columella is pink, dusky pink to purple. The housing size of these animals is between 9 and 13 cm. The soft body has a distinct eel line and varies between pink, gold and light brown. The mesh pattern of the foot is very pronounced.
Lissachatina albopicta
can reach a case size of up to 12 cm. The basic color of the housing is white to yellow and has a clear, dark pattern of spots. The apex is pink to red. The housing looks similar to that of the Lissachatina reticulata and it is also similarly fluted. The soft body is brownish and has a rather indistinct eel line.
Lissachatina zanzibarica
The housing is yellow to gray and has dark stripes. The apex is pointed. The soft body is gray with a darker eel line. This species is viviparous.
Archachatina marginata
with the subspecies Archachatina marginata ovum
This snail has a dark brown shell with a darker stripe pattern. The apex is rounded. The length of the case can vary between 12 and 18 cm. In Arch. Marginata ovum , the columella color and the apex are orange. Here, too, there is an elevation in the form of a “V” at the foot end. The body color can vary in cultivated forms from white without a dark pupil in the eyes (albinotic), white with a dark pupil in the eyes (leucistic) and white with dark stalks and eyes as well as a slightly colored eel line (Amelanistic), in the wild colors in shades of beige , brown to black. The wild colors dominate the inheritance over the light cultivated forms. In these, for example, the Amelanistic color dominates over the leucistic one.
Archachatina marginata suturalis
The Archachatina marginata suturalis is originally from West Africa. It has a soft body that varies from dark to light brown. The casing of this Archachatina has a yellow-brownish color. It can be spotted, but also striped. This is different for each copy. The housing is between 10 and 13 cm long. The apex is pink in color and rounded. Ordinary specimens weigh up to 50 grams. The sexual maturity of this species of snail occurs around the age of one (around 12 months). The area is very small. This snail only lays up to ten eggs on average. Since it occurs more in the west of Africa, it requires a higher temperature in the terrarium or aquarium and higher humidity.
attitude
Especially in England and Ireland , but increasingly also in Germany , Austria and Switzerland , the African giant snails are a popular pet . The reason for this is on the one hand their impressive size and trustworthiness, on the other hand their relatively simple keeping. It is important to plan when purchasing that the snails, depending on the species, can become very large. Giant African snails can be kept of sufficient size in any commercially available terrarium , but you almost always need additional technology to heat the terrarium.
literature
- Andreas Leiß: Agate snails, the Achatinidae family , Natur-und-Tier-Verlag Münster, 2007, ISBN 978-3-86659-029-8
- Heiko Schulz & Robert Nordsieck: The African giant snail Achatina Lissachatina fulica , Natur-und-Tier-Verlag Münster, 2008, ISBN 978-3-86659-085-4
Web links
Individual evidence
- ↑ a b S.K. Raut & GM Barker: Achatina fulica Bowdich and other Achatinidae as Pests in Tropical Agriculture. Chapter 3 in Gary M Barker (editor): Molluscs as Crop Pests. CABI, 2002. ISBN 978 0851993201
- ↑ Banana peels . Portrait on feedipedia.org, a project by INRA, CIRAD, AFZ and FAO, accessed on June 1, 2013.
- ↑ MolluscaBase (2019): MolluscaBase. Achatinidae Swainson, 1840 . accessed on July 15, 2020.
- ^ Andreas Leiß: Achatschnecken, the family Achatinidae , Natur-und-Tier-Verlag Münster, 2007, ISBN 978-3-86659-029-8