| Abstract [eng] |
Invasive species are one of the most important factors affecting not only biodiversity of local species, but also having significant effect to native community structure and functioning. There are 4 non-indigenous freshwater mollusc species recorded in Lithuanian inland waters, where 2 of them are considered as invasive species. One of the invasive species is Potamopyrgus antipodarum, which is rapidly spreading and having a hight demographic potential species in an invasive range. Despite that the species was firstly recorded in Curonian lagoon, more than 60 years ago, the data on species distribution in Lithuanian inland waters, genetic variability, life-history and population traits and functional role in lake ecosystems is very limited. During this study, it was estimated that species is rapidly spreading across the Lithuanian inland waters – during the last 6 years the number of invaded ecosystems increased from 2 to 18. Also, this study indicated that according to mitochondrial and microsatellite DNA populations of P. antipodarum are monomorphic. As it was expected, studies in mesotrophic lake ecosystems revealed, that New Zealand mudsnail is primary consumer which relies mainly on littoral primary production. Also the study indicated hight density and secondary production of the snail for Lithuanian freshwater ecosystems. Both density and secondary production varied not only throughout the year, but also between the lakes. It was also estimated, that despite benthivorous fish species consumed the snail in laboratory conditions, these fishes avoid feeding on P. antipodarum and can hardly significantly contribute to the regulation of its density in field during the initial stages of the invasion. |
