Morphology and phylogeny of Nitzschianandorii sp. nov. (Bacillariophyceae), a new small-celled lanceolate species from a post-mining reservoir.

Post-mining reservoirs are distinguished by characteristic environmental conditions where specific diatom communities can be observed. Reservoirs created as a part of the reclamation plan after human mining activities are marked by unique chemical and physical water parameters. In the course of research on the diatoms from Bogdalów reservoir, we examined the taxonomic and morphological diversity of Nitzschia taxa from the section Lanceolatae occurring in a post-mining lignite reservoir. Our study describes a new species of Nitzschia from a post-mining reservoir, Nitzschianandorii Olszynski, Zakrzewski & Zelazna-Wieczorek, sp. nov. Morphometry and morphology analyses of new species were performed with light and scanning electron microscopy. Chloroplast morphology analysis was conducted with differential interference contrast microscopy and confocal laser scanning microscopy. Molecular data from SSU 18S, rbcL and psbC sequences were obtained from cultures of this taxon. Differential diagnosis of Nitzschianandorii Olszynski, Zakrzewski & Zelazna-Wieczorek, sp. nov. with co-occurring taxa: N.lacuum and N.alpinobacillum was performed using morphological traits and nMDS analysis of the valves' morphometry.

Description of five new Luticola D.G.Mann (Bacillariophyta, Diadesmidaceae) species from Indonesia with comments on the morphological boundaries of the genus.

During a survey of the Indonesian diatoms, five Luticola D.G.Mann taxa that could not be identified, based on the available literature were discovered. Based on light microscopy, scanning electron microscope observations and comparisons with similar taxa, all of them are described as new species. All taxa were found on mosses growing on tree trunks and concrete on the islands of Banda Besar and Seram and from spring on Java Island. Luticolainsularissp. nov. is most similar to L.aequatorialis and L.simplex, but it can easily be distinguished from both taxa, based on the lower striae density, the narrower valves and the well-developed silica ridges on the valve face/mantle junction. Luticolabandanensissp. nov. resembles L.frequentissima, but they can be easily distinguished, based on their valve widths and the direction of the grooves located on the distal and proximal raphe endings. Luticolaellipticasp. nov. is most similar to L.sparsipunctata, L.tenuis and L.bryophila. Amongst all the species compared, L.ellipticasp. nov. is the only one with a highly asymmetrical central area, with the isolated pore located on the wider side. Luticolamalukuanasp. nov. shares similarities with L.dismutica and L.areolata, but it has a notably higher stria density. From L.areolata, it can also be separated by the morphology of striae and the lack of ghost areolae in the central area. Luticolapoliporeasp. nov. is unique in the whole genus due to the presence of multiple isolated pores.

Marine and brackish Luticola D.G.Mann (Bacillariophyta) species from the Java Sea and South China Sea coasts with the description of three new species.

In this study, samples were collected from the Java Sea coasts, from the South China Sea in Hainan Island coasts and Quang Yên region and Rú Chá mangrove near Hue in Central Vietnam. In studied samples a total of eight Luticola species have been observed. Three of the taxa studied are described herein as species new to science - Luticolaorientalis sp. nov., L.cribriareolata sp. nov. and L.halongiana sp. nov. Under light microscopy (LM) L.orientalis sp. nov. and L.cribriareolata sp. nov. are similar with rhombic-lanceolate to rhombic/ elliptic-lanceolate to elliptic valve shapes and narrowly rounded apices. Both species can be easily distinguished by stria density (higher density in L.orientalis). Under SEML.cribriareolata is characterized by cribrate areola occlusions, a character thus far observed only in three established species. The remaining species of the whole genus known thus far are characterized by hymenate areola. Similar morphology Luticola species have been observed from tropical mangrove forests from Madagascar but they all can be easily distinguished based on the lack of grooves in the central area. The third species - L.halongiana sp. nov. has rhombic-elliptic to rhombic-lanceolate valves with broadly rounded to slightly protracted apices in larger specimens. This species has a relatively broad central area. Also unique among brackish-water Luticola is the small, rounded stigma positioned almost midway between the valve center and valve margin. In the habitats from which the new species are described we also identified five established Luticola taxa including, L.belawanensis, L.celebesica, L.inserata, L.seposita and L.tropica. For those species we provide detailed SEM characteristics of valve ultrastructure, as well as the range of environmental conditions and geographic distribution within the study area.

Description of four new terrestrial diatom species from Luticola and Microcostatus genera from South Africa.

The knowledge about terrestrial diatom assemblages in southern Africa is rather limited, despite a long history of diatom research in this area. Terrestrial habitats are places of characteristic diatom floras, dominated by species resistant to desiccation which are able to thrive in conditions of limited water availability. The presented work expands the knowledge about these unique habitats. During the study on terrestrial moss-inhabiting diatoms from Western Cape Province (South Africa), four taxa with a unique set of valve features have been found and described herein as new species, based on light and scanning electron microscopy. These new species are: Luticolamicrocephala M. Rybak, Peszek & Kochman-Kedziora, sp. nov., Luticolaasymmetrica M. Rybak, Kochman-Kedziora & Peszek, sp. nov., Luticolaterrestris Kochman-Kedziora, M. Rybak & Peszek, sp. nov. and Microcostatusmeridionalis Peszek, M. Rybak & Kochman-Kedziora, sp. nov. Algal community composition had low species richness (9-15 taxa per sample) and samples were dominated by: Humidophilacontenta, Nitzschiabrevissima and Eunotiaaff.pseudominor. The three new Luticola species formed numerous populations, exceeding 10% of the share, whereas Microcostatusmeridionalis reached 5.4%. Basic morphological data of associated diatom flora together with detailed micrographs are also provided.

Three new Luticola D.G.Mann (Bacillariophyta) species from Rapa Nui (Easter Island) found in terrestrial diatom assemblages dominated by widely distributed taxa.

BACKGROUND: Rapa Nui (Easter Island = Isla de Pasqua) is of volcanic origin, best known for about 900 man-made stone statues known as moai. It is one of the most isolated inhabited islands on Earth and studies on the diatoms of Rapa Nui are very few. METHODS: Light (LM) and electron microscopic (SEM) observations of a single sample collected from Rapa Nui are presented. The samples (mix of soil and organic detritus) were collected from ground of cave entrance. RESULTS: The samples were characterized by low diatom diversity and strongly dominated by terrestrial (soil) forms. Among the taxa present in the material studied were cosmopolitan forms of the genera Humidophila, Nitzschia, Angusticopula, Orthoseira, Tryblionella and Luticola. Whereas most of taxa of the enumerated genera were identifiable, only one among four Luticola species distinguished in the samples studied was identified. This taxon was L. ectorii, a cosmopolitan species known previously from South America (Brazil) and Asia (China). The three remaining species could not be assigned to any established species. Therefore, based on external and internal morphological features from light and scanning electron microscopic analysis, we describe here three species new to science, including: L. georgzizkae, L. rapanuiensis and L. moaiorum. All three taxa new to science are compared to established Luticola species and their significance for the global distribution of the genus is discussed.