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P.G. Ryeznik E.P., Khaylenko O.V.
Tavrida national university n.a. V.I.Vernadsky, Simferopol, AR Crimea, Ukraine
PROBLEMS OF BIO INDICATIONAL USE OF MOLLUSCS GENUS HELIX AND EOBANIA IN URBANIZED ECOSYSTEMS OF CRIMEA CITIES
Ground mollusks amaze us with diversity of forms, intraspecific variability, habitat area, simple conditions in labs and farms. All this characteristics make snails ideal objects for different zoological and ecological research. As for the exemplars of mollusk family Helicidae, they are the biggest snail exemplars. Number of species, living on territory of Crimea - 4: Helix pomatia, Helix lucorum, Helix albescens and Eobania vermiculata. Examples of the first specie has disappeared for the last decade (although there were many attempts to settle them on the whole Crimea), second specie lives in highly specialized areas of acclimatization (Bahchisaray area along Belbek river, Kara-Dag nature reserve, Yalta mountain - forest resort and along vineyards of Sevastopol area), Helix albescens and Eobania vermiculata spreads everywhere and almost evenly on the territory of the whole Crimea peninsula. The development of civilizationáis continuouslyáconnected with the processáof urbanization.áAccording to the forecastsáof manyábiologists,áthe total area ofáan urbanizedáareaáof the globeáby 2050áwill amount toámore than 30%áof the territory assignedáto liveáon land.áZooecologicalástudyáurban ecosystemsáhaveáboth scientificáand practical importance .The process of urbanizationáleads to a change, and oftenáthe destructionáof natural habitats.áWhileáformingáurban, suburbanáand gardená-áparkáas a separateágroup of man-madeábiogeocenoses,á that are beginning to study by scientists around the world.
Poorly studiedáthe effect of urbanizationáandámanyáman-made factorsáandábarriers in theáanatomicaláandáconchological parameters of snail examples of citiesáandáareasáunoccupiedáby people.
As is known,áterrestrial mollusksáareánaturalábio indicatorsáof changes, including the human impactáon vegetation andásoil.
In a shell and body of snail accumulate a range of chemical elements: copper, lead, zinc, strontium, which are main components of environmental contamination. Interesting fact that, even with long anthropogenic influence on this small animals, it almost don't influence the species composition and amount in urban malco-fauna, because mollusks has high level of adaptation (third place after scorpions and roaches) to high concentrations of some chemical elements.
Problem of snail expansion in city that snails are sedentary animals and they can't expand naturally. City biotopes: parks, public gardens, well landscaped streets, Óand suburban plantations populated by individual commensal snail species [1,2]. The problem itself is that while creating park no one thinks about mollusk introduction and that urban conditions are not suitable for mollusks. Second big problem - weak and often entirely absent leaf litter, presence of old and raw trees in park, hemps, overgrown shrubs, in which the snails live, hide from adverse weather conditions and where they can spawn caviar/eggs, that is to acquire offspring.
The most important in snail life are land cover and soil salinity, also moisture and climate conditions.
We should consider the fact that when we use snails as natural bio indicators, we should watch for variability of land cover and consider adverse conditions for snails: dry hot summer and long absence of rainfall [3,4].
The ability to useáthe snailsáasábio-indicatorsáof urbanáformáis limitedáináseveral importantáfactors: theáhistory of theácity, the state ofáurban floraáand fauna, infrastructure developmentáand developing newáareasáof the city [5,6].
1. Leonov S.V. Influence of habitat conditions on size-age structure of populations of ground mollusk (Gastropoda; Pulmonata) Helix albescens Rossmassler, 1839 in Crimea // Ecology: from genes to eco systems.- Ekaterinburg, 2005.- P. 152-153.
2. Leonov S.V. Distributionáof commonásnailáin the Crimeaáandáthe definition ofábiomassáof individualásettlements // Science notes áTNU n.a. V.I.Vernadsky.- 2001.- Ď. 14 (53), ╣ 1.- P. 75-79.
3. Ryeznik E.P. Influence of anthropogenic stresses on mollusk specie Eobania vermiculata (Muller, 1774) in conditions of Simferopol city and its area - Collection ofámaterials of the firstáintercollegiateástudent conference "Economic potential of my country", - Sevastopol. - "SEU", 2010. - P. 27
4. Hohutkin I.M. Structure of species variability on the example of ground mollusks.- Ekatirinburg:á RSA, 1997.- 176 p.
5. Popov V. N., Zarochentzev G. A. Interspecific variation in resistance to dessication of four species land snail genus Helix (Gastropoda; Pulmonata) // Abstracts of 12 Intern. Malacological congress. - Vigo, Spain, 1995. - P. 495-496.
6. Turček F.I. Studies on the ecology and production of the Roman snail Helix pomatia L. // Biologia (ČSSR), 1970.- 25, N2.- P. 103-108.