Results of Research on the Active Species Protection of the Roman Snail (Helix Pomatia, Linnaeus, 1758) Using Farmed Snails in the Second Year of Life. First Season of the Study

Abstract

The effect of three forms of active species protection in the Roman snail were studied. On the “source plot” the natural population was supported by introducing hatchlings of farmed Roman snails aged 1+, bred from adult specimens of this population. These hatchlings (age 1+) from “source plot” population were also introduced to the following two natural plots: to the “empty plot”, where the population was formed by introduction of farmed Roman snails in the second year of life (1+) into a selected area which had been emptied of the natural population; to the “inhabited plot”, where farmed Roman snails aged 1+, originating from breeding snails of the foreign population from a “source plot”, were introduced to the local natural population. It was established that introducing Roman snails aged 1+ and bred under farm conditions has a clearly positive influence on the age structure of the natural population in the studied plots. The rate of growth of these snails adjusted to the rate of growth of the specimens in the same age group belonging to the natural population. The farmed Roman snails grew most rapidly in the “empty plot” sown with fodder vegetation, more slowly in the “source plot” with access to appropriate herbaceous vegetation, and most slowly in the “inhabited plot”. The attempt to create a naturalized population in a specially adapted “empty plot” without the natural population was successful. This was determined not only by a large number of hiding places from calcareous stones available to the Roman snails but above all by the species structure of the herb flora, which met their nutritional requirements as it contained high proportions of plants such as Brassica rapa × Brassica rapa subsp. chinensis, white clover (Trifolium repens), red clover (Trifolium pratense) and the hybrid of lucerne (Medicago × varia Martyn)

Morphometric traits of shells determine external attack and internal utilization marks in the Roman snail in eastern Germany

“…The Roman snail (Helix pomatia Linnaeus, 1758) is of considerable commercial interest as human food (also called "edible snail"; Bloszyk et al, 2010;Gheoca, 2013) and in medical research (Dwek et al, 2001). Exploitation by humans is a potential cause for population declines (Welch and Pollard, 1975;Andreev, 2006), especially as the species has a relatively slow reproduction and maturation rate (Ligaszewski et al, 2014) and long dormancy periods (Lind, 1989). Nevertheless habitat destruction (Andreev, 2006) and a changing climate (Nicolai and Ansart, 2017) may threaten H. pomatia populations in the future as well, particularly in areas with unfavourable soil conditions.…”

“…Nevertheless habitat destruction (Andreev, 2006) and a changing climate (Nicolai and Ansart, 2017) may threaten H. pomatia populations in the future as well, particularly in areas with unfavourable soil conditions. Those conser-vation concerns resulted in the development of breeding programmes to protect the species (Hardouin, 1995;Ligaszewski et al, 2014). National and EU-level regulations address overexploitation by creating different protection categories (Bouchet et al, 1999;Ligaszewski et al, 2016).…”

“…Those conser-vation concerns resulted in the development of breeding programmes to protect the species (Hardouin, 1995;Ligaszewski et al, 2014). National and EU-level regulations address overexploitation by creating different protection categories (Bouchet et al, 1999;Ligaszewski et al, 2016). National regulations protect H. pomatia in Germany (Bundesartenschutzverordnung (BArtSchV) Paragraph 1 Satz 1) and control the collection of snails, but they do not implement specific conservation programmes.…”

Reproduction of the Roman snail (Helix pomatia L.) from a local natural population in farm conditions and in a natural habitat

“…These were successfully continued in conjunction with multi-year studies aimed at developing principles for active protection of a selected local natural population of Roman snails. The basis for this protection was the introduction into the natural habitat of partially reared hatchlings from this same population which had been obtained on a mass scale in farmed conditions (Ligaszewski et al, 2005, Ligaszewski et al, 2007, Ligaszewski et al, 2014a, Ligaszewski et al, 2014b, Ligaszewski et al, 2016. These studies allowed for the determination of the precise values and fluctuations of such values as clutch weight, number of eggs in clutch, mean weight of a single egg, ratio of clutch weight to breeder weight, and seasonal variability in the intensity of reproduction.…”

Persistence of local populations of the Roman snail (Helix pomatia L.) for 15 years in conditions of moderate and constant anthropogenic impact – A case study from Central Europe

“…The species is often farmed (williams 2009, neuBert 2013), but wild populations may still be harvested in some countries, including Poland. However, there are legal restrictions in place and national authorities have a duty to monitor populations of this species and ensure that such monitoring is effective in determining acceptable levels of exploitation (ligaszewski et al 2014(ligaszewski et al , Błoszyk & kalinowski 2015. In Poland, these restrictions and duties are laid out in the Regulation of the Minister of Environment dated 6 October 2014 (regulation 2014) on protecting animal species.…”