Mediterranean field snail
| Mediterranean field snail | ||||||||||||
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Mediterranean field slug ( Deroceras panormitanum ) |
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| Scientific name | ||||||||||||
| Deroceras panormitanum | ||||||||||||
| ( Lessona & Pollonera , 1882) |
The Mediterranean field slug ( Deroceras panormitanum ) is a slug belonging to the family of field slugs . It used to be found only in the Mediterranean area, but today it is found in large parts of Western and Central Europe. They can be found in gardens, parks, fields and in the wasteland.
features
This Mediterranean field slug is stretched out 3 to 4 cm long (other authors state 2.5 to 3.5 cm). The coat is relatively large and takes up about 40 to 45% of the total body length. The breathing hole is located in the back of the mantle and, unlike other species, is relatively small. The edge zone of the breathing hole is set off slightly from the coat by a lighter color. When the animal is stretched out, the head and neck extend unusually far in front of the coat. A short, truncated keel is formed at the top of the foot. The color is extremely variable, it varies from light and dark brown to slightly reddish. Occasionally there are also gray-brown, gray to almost black specimens. Sometimes the coat also shows a faint pattern of spots. The light gray to cream-colored sole usually has darker edge zones; only in very light animals is the sole almost uniformly light gray to cream-colored. The animals are very active and hit their tails violently when stimulated.
Reproduction
The Mediterranean field snail only has one reproductive period during which it mates several times. Mating lasts around an hour and a half, with foreplay taking up the longest. The animals hit their tails violently and bite each other. Just a few days later, the field snail lays several clutches in which the number of eggs varies greatly. As the snail gets older, it lays clutches with very few eggs until the egg-laying process has ended completely. Self-fertilization also occurs but is rare. The Mediterranean field snail can reach sexual maturity as early as eight weeks after hatching. The average generation time is four months. Therefore up to three generations (more often only two) can be formed per year.
Occurrence and distribution
The Mediterranean field snail is mainly found in cultivated land, in gardens, parks, but also in wastelands. It occurs mainly in the lowlands and hill country. The diet consists of fresh plant material and fruits. Originally, as the name suggests, it was restricted to the Mediterranean region from Spain to Greece. In the 1970s, the Mediterranean field snail was introduced to Germany and is rapidly expanding its range. Today's distribution area extends in the west to Ireland, the British Isles, western and northern France, the Benelux countries, in the north to Sweden and Finland (here often in greenhouses). Today the species has also been introduced to other parts of the world. In Australia, it is found in almost every state. It is also widespread in New Zealand. In the United States, it was recently detected near Washington DC.
Research on the Mediterranean field snail
For many years, the Görlitz State Natural History Museum has been breeding the Mediterranean field snail for research purposes. There are three different color morphs :
- the natural color variant
- Albinos, they have white, translucent skin and unpigmented eyes.
- "Blackeye", they differ from the albinos only in the feature of the eyes, which are pigmented in them. Hence the name.
The last two color morphs are mutants and were bred in the Natural History Museum for research purposes. Inheritance follows Mendel's laws, with the brown color morphs being dominant over the others. The unpigmented field snail is inherited recessively to the Blackeye.
The Mediterranean field slug is an ideal laboratory animal because it is easy to keep in laboratory conditions. The generation time averages four months, which is relatively short. The field snail reaches sexual maturity around eight weeks after hatching and can then be used for the experiments. The animals are easy to mate and can be easily observed. Since many snails use their own sperm to fertilize their eggs, the color morphs can in many cases determine or rule out self-fertilization in the offspring.
Systematics
There are two synonyms for this species: Deroceras caruanae Pollonera, 1891 and Deroceras pollonerai (Simroth, 1889). They were still considered to be separate species in 1985. Wiktor (2000) considers the three species to be one species, Deroceras panormitanum Lessona & Pollonera, 1882.
The Mediterranean field slug as a pest
The Mediterranean field snail is now perceived as a pest in some regions of Central Europe and its control is recommended. In New Zealand the species is also considered a pest.
Individual evidence
- ↑ Fechter and Falkner, p. 192
- ↑ Kerney et al., P. 194
- ↑ CSIRO
- ↑ GM Barker: Molluscs as Crop Pests. 468 pp., Wallingford CABI Pub, Oxon, UK; New York, NY, 2002 ISBN 0-85199-320-6
- ↑ Reise, Hutchinson und Robinson (2006) ( Memento of the original from September 27, 2011 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ [1]
- ↑ Remating, paternity and fecundity in Deroceras panormitanum Ines Schulze, Barbara Jäschke, Josefine Sauer, Christiane Matthieu, Sabrina Matton & John Hutchinson
- ↑ Leaflet on harmful snails in house and allotment gardens. (PDF, 75kB) Thuringian State Agency for Agriculture, 2004, accessed on May 10, 2013 .
- ↑ GM Barker: Molluscs as Crop Pests. 468 pp., Wallingford CABI Pub, Oxon, UK; New York, NY, 2002 ISBN 0-85199-320-6
literature
- Michael P. Kerney, RAD Cameron & Jürgen H. Jungbluth: The land snails of Northern and Central Europe. 384 pp., Paul Parey, Hamburg & Berlin 1983 ISBN 3-490-17918-8
- Rosina Fechter and Gerhard Falkner: molluscs. 287 pp., Mosaik-Verlag, Munich 1990 (Steinbach's Nature Guide 10) ISBN 3-570-03414-3