Original paper
Molecular phylogeny of the diatom genus Envekadea (Bacillariophyceae, Naviculales)
Maltsev, Y.; Andreeva, S.; Kulikovskiy, M.; Podunaj, J.; Kociolek, J.P.
Nova Hedwigia, Beihefte Beih. 146 (2018), p. 241 - 252
36 references
published: Jan 3, 2018
Abstract
Envekadea is a new genus of diatoms recently split off from the catch-all genus Navicula. This new genus is distinct, being biraphid, symmetrical to both the apical and transapical axes, having a sigmoid raphe and uniseriate striae composed of rounded to angular areoale that possess external hymenate occlusions. There are six known species in the genus, and they together occupy a wide ecological breadth. However, phylogenetic position of this new genus is uncertain. In this paper the morphology and ultrastructure of two new Envekadea pseudocrassirostris strains are presented and discussed. Studied samples were collected from a brackish lake in Indonesia. In the present report we offer new data based on a molecular investigation of Envekadea and remarks on its systematic position within the raphid diatom phylogenetic tree. In a two-gene (18S rDNA fragments and partial rbcL gene) phylogenetic analysis, Envekadea was most closely related to members of the genera Pinnularia and Caloneis. We propose to place Envekadea in the family Pinnulariaceae. We discuss these results in the context of the morphological similarities and differences between Envekadea and its closest phylogenetic allies.
Keywords
diatoms • ecology • Envekadea • morphology • phylogeny • Indonesia