Navicula similecataracta-rheni sp. nov. and N. aquitanonipponica sp. nov. (Bacillariophyta), two new species from Nouvelle-Aquitaine, Southwestern France - comparison with the related species N. cataracta-rheni Lange-Bertalot, N. cryptotenella Lange-Bertalot and N. sancti-naumii Levko et Metzeltin

Abstract

: Navicula similecataracta–rheni and N. aquitanonipponica are two new Navicula species recorded from the Nouvelle Aquitaine Region, southwestern France. Both new species belong to the linear–lanceolate Navicula species complex. A detailed iconography based on light and scanning microscopy observations is given for the type and complementary populations. Comparisons with close related species based both on literature and on microscope observations, particularly with N. cryptotenella , N. cataracta–rheni and Navicula sancti–naumii , support the erection of the two new species.