Spotted garden snail
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Spotted garden snail ( Cornu aspersum ) |
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| Cornu aspersum | ||||||||||||
| ( Müller , 1774) |
The spotted garden snail ( Cornu aspersum , Helix aspersa , Cryptomphalus aspersus or Cantareus aspersus ) is less known in Central Europe than its larger relative, the garden snail ( Helix pomatia ). The reason for this may be primarily the range of this species, because it prefers a milder climate, i. H. the Mediterranean and Atlantic coastal areas. However, it became widespread through trafficking, so it can now be found in South Africa, New Zealand, North America, and Australia. The species is often assigned to the genus Cornu Born, 1778 by Central European authors . Italian authors place it in the genus Cantareus Risso, 1826. In molecular studies, in breeding and in southern European specialist publications, Helix aspersa is often used .
Appearance
The spotted garden snail is best described in comparison to the Helix pomatia . If you put two adult animals of both species next to each other, you can clearly see that the shell of the spotted garden snail remains somewhat smaller than that of the Helix pomatia . The spotted Roman snail reaches a maximum size of about 4 cm measured from the apex to the housing mouth, while the Helix pomatia is about 5 cm in diameter and 6 cm possible.
The color and surface of the shell are sometimes very different from one another, because the shell of Cornu aspersum is rough, almost "wrinkled" and covered by a characteristic pattern that gave the spotted garden snail its name. The pattern of dark brown stripes and checked patterns on a light, horn-colored to brownish background (similar to that of the indigenous spotted snail Arianta arbustorum ) gives the entire shell a rather darker touch.
The soft body itself is usually light gray to black in color, with a slightly darker eel line clearly visible. Compared to Helix pomatia , the furrow on the top of the foot is far less deep and clearly marked.
Food and way of life
In terms of their habitat requirements, the spotted garden snails are relatively tolerant. This is evident not only in their wide spread, but above all in the diversity of the habitats they inhabit. In fact, Cornu aspersum can be found up to heights of 1000 m above sea level and inhabits heaths and meadows as well as forests, gardens, parks, dunes and rocky areas.
This tolerance is partly due to the fact that the spotted garden snail is less bound to calcareous soil than its larger relatives due to its smaller shell and the lack of a winter cover ( epiphragma ).
Since the spotted garden snail is adapted to a life in the Mediterranean area, it can often not survive too cold winters - as they occur in Germany, Austria and Switzerland. One of the reasons for this is that, unlike Helix pomatia, the red Roman snail does not form a thick lime cover with which it can close its housing opening over the winter as protection against cold and drought. Instead, it covers the opening in the housing with a thin mucous membrane that sticks to the air. Temperatures below 5 ° C are unsuitable for the spotted garden snail.
Reproduction
The spotted Snail is hermaphroditic ( hermaphrodite ), that is, each individual has both male and female sex organs and can therefore act at the copulation both males than females. When making love, both partners press the soles of their feet together - this can be done in a lying position, as in the case of Central European tree and garden snails, or in a raised position, as is common with Helix pomatia . As a stimulus, the partners push so-called “ love arrows ” made of lime into each other's feet. This will inject a hormone secretion into the partner. The penis of a spotted garden snail is shaped significantly differently than that of a common garden snail.
Like the Helix pomatia, Cornu aspersum lays its eggs in self-dug burrows from which fully developed juvenile snails and shells hatch after a few weeks, which remain in the ground for some time until they are strong enough to hit the surface (approx. 20 days).
meaning
Cornu aspersum finds its importance for humans (like Helix pomatia ) mainly in breeding for food purposes . In French snail breeding, the spotted Roman snail even represents the far larger part of breeding animals compared to the common Roman snail. For this purpose, own breeds have been developed, some of which are twice as heavy as the original snails.
In addition, much like African giant snails , the spotted garden snail is becoming increasingly popular as a pet (especially in England).
The spotted garden snail is an intermediate host for the cat lungworm Aelurostrongylus abstrusus and a factor in the increasing spread of aelurostrongylosis .
attitude
The spotted garden snail is one of the relatively easy to keep terrarium animals. An aquarium can be covered with a hobby glass plate available in the hardware store, in which holes about 10–15 0.6 cm in size have been previously drilled to ensure the supply of oxygen. An aquarium has the advantage that all furnishings are accessible from above. In addition, it can be opened at any time, which is not the case in a terrarium, because there are sometimes some snails sticking to the sliding doors, which would then be injured if they were opened. Regardless of whether an aquarium or terrarium is available, the size for 3–8 animals should be at least 60x30x30 cm, because Cornu aspersa are very active. Group keeping with at least three animals is necessary because they are not loners, need a mating partner and otherwise like to be close to each other. An earth-like soil substrate (not fertilized!), Ideally molehill soil, which can be additionally limed up under certain circumstances, is recommended. The so-called "coconut humus", which is available in many pet shops, is suitable. Since this is acidic, it should be limed up with calcium carbonate - but never with calcium hydroxide , which is also available, but has an excessively alkaline reaction and can injure or even kill the snails if they are on the ground. Coconut humus is particularly suitable for people who do not want to have any microorganisms such as springtails in the terrarium. Spotted garden snails feel particularly comfortable in a facility with branches, pieces of bark and moss, which give the terrarium similarities with the forest floor. If necessary, these furnishings can be heated under supervision for 10 minutes at 125 ° C in the oven so that bacteria, parasites and fungi die off. The facility offers the snails the opportunity to hide, because they like it shady and humid. It is therefore important that the terrarium is regularly sprayed with clear water, ideally rainwater. The humidity should be between 55 and 70% and the temperature in the terrarium should not exceed 26 ° C.
All types of fruit and vegetables are suitable for feeding, but they should be washed thoroughly beforehand and cleaned of insecticides and pesticides . Proteins should be fed, but only in very small amounts and no more than once a month. For example, the protein of a boiled egg or gammarus , which is offered in pet shops as a food supplement for turtles, is suitable. A mixture of lime powder, flour, sugar and water or commercially available sepia shells are suitable for adding lime . The shells of boiled eggs are suitable for adding lime because they consist to a large extent of calcium carbonate .
In the winter months, the spotted garden snails should be given the possibility of winter rigor. Due to the local climate, however, they cannot be put outside - like other snail species. On the other hand, cool cellar rooms are suitable because the temperature should be around 10 ° C. You should make sure to water the substrate at least 1–2 times a week, because the snails can wake up due to temperature fluctuations and then absolutely need moisture. Spotted garden snails do not cover themselves up like the native Helix pomatia , but only form a thin skin from which the moisture can escape faster. That is why they need a moist environment despite the winter rigor.
Illustrations
Young spotted snails on a lettuce leaf.
Spotted garden snail from the front.
Rare left-handed shape, so-called "snail king", and normal right-handed shape; Incidence left to right wound: 1: 40,000.
swell
literature
- Klaus Bogon: Land snails. Biology, ecology, biotope protection. Natur Verlag, Augsburg 1990, ISBN 3-89440-002-1 .
- Jürgen H. Jungbluth, Dietrich von Knorre: Common names of land and freshwater mollusks in Germany (Gastropoda et Bivalvia). In: Mollusca. 26 (1), Dresden 2008, pp. 105–156. ISSN 1864-5127 (PDF)
- Michael P. Kerney, RAD Cameron, Jürgen H. Jungbluth: The land snails of Northern and Central Europe. Paul Parey, Hamburg / Berlin 1983, ISBN 3-490-17918-8 .
- Rosina Fechter, Gerhard Falkner: Mollusks. (= Steinbach's nature guide. 10). Mosaik-Verlag, Munich 1990, ISBN 3-570-03414-3 .
Individual evidence
- ↑ Helix aspersa. In: OF Müller: Vermivm terrestrium et fluviatilium, seu animalium infusoriorum, helminthicorum, et testaceorum, non marinorum, succincta historia. Volume alterum. Heineck & Faber, Leipzig 1774, p. 59.
- ↑ cf. the "Cornu problem" by Robert Nordsieck
- ^ F. Giusti, G. Manganelli, PJ Schembri: The non-marine molluscs of the Maltese Islands. (= Museo Regionale di Scienze Naturali. Monograph 15). Torino 1995, ISBN 88-86041-24-1 .
- ↑ G. Manganelli, M. Bodon, L. Favilli, F. Giusti: Fascicolo 16. Gastropoda Pulmonata. In: A. Minelli, S. Ruffo, S. La Posta: Checklist delle specie della fauna italiana. 1995, pp. 1-60.
- ↑ CR Altaba: Hi ha caragols endemics de Menorca? In: Malacofauna Balearica. 11, 2007, pp. 5-15.
- ↑ D. Dhora: Regjistër i specieve tė Faunes Së Shqipërisë. In: Register of species of the fauna of Albania. Camaj-Pipa, Shkodër 2009, pp. 1–128.
- ↑ HM Elsheikha et al .: Update on feline aelurostrongylosis and research priorities for the next decade. In: Parasites & vectors. Volume 9, number 1, 07 2016, p. 389, doi : 10.1186 / s13071-016-1671-6 , PMID 27387914 , PMC 4936016 (free full text) (review).
- ↑ Angus Davison, Philippe Thomas: Internet 'shellebrity' reflects on the origin of rare mirror-image snails . In: Biology Letters . The Royal Society, June 3, 2020, doi : 10.1098 / rsbl.2020.0110 (English, royalsocietypublishing.org [accessed June 5, 2020]).
