A new species of Didymosphenia (Bacillariophyceae) from the Western Carpathian Mountains of Poland and Slovakia
Mrozińska, Teresa; Czerwik-Marcinkowska, Joanna; Gradziński, Michał
Didymosphenia tatrensis is described as a new species from the Western Carpathians of Poland and Slovakia. It was found in 2004 in the calcareous part of the Tatras in the Kościeliski and Siwa Woda Streams in Poland and in the Biela Stream near the villages of Ždiar and of Tatranská Kotlina in Slovakia. It also occurred in the adjacent intra-montane basin in the Białka and Dunajec Rivers (in the vicinity of Sromowce Niżne). The new species is morphologically similar to D. siberica, D. pumila and D. curvata. However, it most closely resembles D. siberica from which it differs by dimensions (usually extreme length) and by density of striae. It differs from it and the species mentioned above, by the position of the areolae (they are not found on the surface of the valve but deeply depressed within the valve). The areolae may be round, oval or even longitudinally oval. The new species was found in association with D. geminata, which dominated in the Biela Stream and in the Białka and Dunajec Rivers. In the Koś cieliski and Siwa Woda Streams, D. geminata occurred together with D. tatrensis and both species were present in small numbers.