Alien Mollusca In Serbian waters

1. Alien Mollusca In Serbian waters Environmental protection and Water ManagementResearch Institute (VITUKI Kht),Budapest, Hungary BALWOIS, 25–29 May, Ohrid

2. Introduction Aquatic biotopes are due to its unique features, among the most disposed ecosystems to bioinvasions; Among non-indigenous taxa recorded in Serbian waters, Mollusca were found to be among the most prospective invaders ; Alien species (exotic, non-indigenous) - are species or organisms that are not native to a locality, having been moved there from its natural range by humans or other agents ; These species once established in a new environment may multiply, spread over large areas, compete with native organisms, modify local habitats and effect ecosystem functioning ; Main pathways (activities involved in the spread of alien speciees) that have been identified as significant for the introduction of alien species are: shipping canals, ballast water, ship hull fouling, aquaculture, stocking and ornamental trade ;

3. Aim of work To present alien species of molluscs ; To give information about their distribution within the most ; important waterway in Serbia (the Danube, the Sava and the Tisa Rivers); Discuss vectors and pathways of distribution; Why focus on Freshwater Molluscs Freshwater molluscs provide food and products ; Key component of freshwater ecosystems filtering the water and providing critical ecosystems services ; Critical habitat for commensal species ; Food sources for other animals in the ecosystem; Act as intermediate hosts for parasites that can carry serious diseases ;

4. Area of investigation: Danube, Tisa and Sava Rivers Serbian reach of Danube covers middle and a part of lower waterway ; Danube as the “Southern Invasive Corridor” an important branch of the Main European Invasive Network ; Main tributaries are: the Tisa River left –hand and the Sava River right-hand isthe largest tributary of the Danube River in Serbia ; Investigation projects Four international (Joint Tisza Survey, AquaTerra, Joint Danube Survey and Joint Danube Survey 2) and one national expedition (Sava Survey 2006)

5. Invasion corridors

6. Results Within the investigated waterways six alien molluscs taxa were recorded - five species of Bivalvia and one of Gastropoda;

7. Dreissena bugensis Dreissena polymorpha Physella acuta Sinanodonta woodiana Corbicula fluminea Corbicula fluminalis

8. The introduction and spread of the species:Sinanodontawoodiana–correlated with the introduction of the Grass Carp from China ; Corbiculafluminalisand Corbiculaflumineaseems to be connected with shipping,, as well as with the introduction of fish species from Asia ; Dreissenabugeensisand Dreissenapolymorpha(Ponto-Caspian)was introduced by canal and successfully co-exists with other alien molluscs; Physellaacuta–was introduced by ornamental trade ;

9. Discussion and conclusions Lower number of alien taxa was detected in investigated tributaries, which confirms fact that Danube as part of Southern Invasion Corridor represents the most important spreading route and important trajectory for spreading allochthonous invasive species. The fast dispersal of molluscs taxa along the investigated area confirmed the theory that waterways are suitable recipient areas for bioinvasions. Invasion of alien species is one of the most important factors endangering global biodiversity, which reduces the uniqueness of regional fauna .

10. Lithoglyphusnaticoides(Pfeiffer, 1828), status of this species in the Serbian waters is under discussion, therefore we consider it cryptogenic; We could expect new invader Potamopyrgusantipodarum(Gray,1843), species which was introduced into Europe from New Zealand. It is the most widespread non-indigenous molluscs .

11. Thank you for your attention