Arachnologische Mitteilungen 54

36 V. Ivanov, O. Prishepchik & E. Setrakova in the Czech Republic, the few known populations live in the littoral zone of ponds and cut-off meanders (Buchar & Růžička 2002). It is known that practically no specialists in Belarus have ever tried to find D. plantarius intentionally and it was often collected occasionally while scientists were con- ducting other more general research. In fact, there was no spe- cific work ever devoted to spiders of fens or bogs in Belarus. Despite the fact that our, and previous, investigations have not yielded many specimens it is obvious that D. plantarius is widespread in Belarus. In short, it is present everywhere except for the north-east of the country. In 2013 we travelled through several districts of the Viciebsk region including the Western Dźvina and Dzisna rivers and did not find any spe- cimens. However, our investigation was very short and we cannot be sure that D. plantarius is absent there. In additi- on, such large rivers as the Western Buh, Drysa, Uła, Ubarć, Druć, Pina, Łań, Ščara and many others have never been exa- mined along with numerous fens and lakes in the territory of Belarus. Another important observation is that both species of Dolomedes may occur simultaneously within the same bio- tope. Such results were reported before (Holec 2000), but in this case the author was very careful in stating that the species coexist.We observed no differences in patterns of distribution of the two species and it seems that it is common for both of them to share the same biotope. At least within three of the most densely populated biotopes (the rivers Vilija, Biesiedź and Zvaniec fen) D. plantarius and D. fimbriatus were found together.The next step is to look at the dynamics of both spe- cies in order to evaluate competition rates and their actual preferences in terms of abiotic factors. It is our strong belief that Belarus has many potential sites where D. plantarius might be present and that its po- pulations are big and healthy. Previous lack of records is ex- plained simply by lack of interest from the side of specialists and amateurs as well as a lack of specialists themselves. It is obvious that the importance of Belarus for conservation pur- poses is underestimated by specialists from Western Europe, while the country has plenty of water bodies suitable for the species. There are more than 20 000 rivers, 10 000 lakes and numerous swampy areas (more that 14 % of the territory of the country!). The territory of Belarus is practically equal to the territory of Great Britain but the human population is 6 times lower which ensures the safety of natural biotopes simply by the inability to destroy it. Also, 8 % of the territory is already protected and as soon as D. plantarius is included in The Red Book of Belarus every record is a legal reason to confer conservational status to a particular territory and increase the total amount of protected areas. Models that predict distribution and dynamics of D. plantarius in Europe (Leroy et al., 2013) underestimated the presence of the spe- cies in Belarus and probably the calculations were slightly wrong, however, the general trend is correct. If the populati- ons will shift in time to the east and north of Europe due to climate change, newcomers will find the sites already occupi- Tab. 1: Summary of our records of D. plantarius in Belarus Date Water body Coordinates D. plantarius ) / ( 09.07.2012 Nioman river 53°26'30.2"N 24°44'23.9“E -/1 09.08.2012 Jaselda river 52°07'02.68"N 26°26'44.83"E -/1 25.06.2013 Planta-2 lake 52°34'29.8"N 23°46'40.0"E 3/- 15.07.2013 Nioman river 53°29'57.0"N 26°39'03.8"E -/1 09.2013 ?, Minsk region ? -/1 12.09.2013 Vilija river 54°46'30.7"N 26°12'36.1"E -/1 05.06.- 18.08.2014 Zvaniec fen 52°04'43.6"N 24°49'51.4"E and 52°05'42.0"N 24°52'55.2“E 3/6 14.06.2014 BSU, pond 53°50'10.7"N 27°28'01.4"E -/1? 06.2015 Rasta river 53°45'93.41"N 30°42'43.61"E 1 specimen per transect 100 × 5 m along both river banks 06.2015 Biesiedź river 53°21'45.24"N 32°26'50.87"E 06.2015 Biesiedź river 53°11'91,839"N 31°54'09,550"E 06.2015 Biesiedź river 53°17'05,78"N 32°11'35,81"E 06.2015 Biesiedź river 53°19'50,78"N 32°00'67,70"E Fig. 2: Dolomedes cf. plantarius from vicinity of biological faculty of BSU. a. habitus; b. epigyne