| 1. |
- Al-Handal, Adil Y, 1952, et al.
(författare)
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Mastogloia wulffii a new diatom (Bacillariophyceae) from the west coast of Sweden
- 2018
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Ingår i: Fottea. - : Palacky University Olomouc. - 1802-5439 .- 1805-4927. ; 18:2, s. 164-169
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Tidskriftsartikel (refereegranskat)abstract
- While collecting epiphytic diatom samples from the west coast of Sweden, a small Mastrogloia species has been observed and could not be matched with any of the described taxa. Based on both light and electron microscopes examination, this species has been described as new, Mastogloia wulffii sp. nov. and included in Mastogloia section Sulcatae. This species is very small with valve length not exceeding 16.3 mu m. It is characterized by having a narrow, almost straight median depression on both sides of the sternum-raphe, no marginal ridge and with rounded areolae on valve mantle as well as having completely hyaline lateral sterna. A comparison with similar taxa is given. M. wulffii is a marine species growing in moderate numbers on the red alga Polyides rotunda which is widely distributed along the coast of Vrango Island, Sweden.
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| 2. |
- Kahlert, Maria, et al.
(författare)
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The potential of High-Throughput Sequencing (HTS) of natural samples as a source of primary taxonomic information for reference libraries of diatom barcodes
- 2018
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Ingår i: Fottea. - : Palacky University Olomouc. - 1802-5439 .- 1805-4927. ; 18, s. 37-54
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Tidskriftsartikel (refereegranskat)abstract
- Diatoms are used routinely to assess pollution level in rivers and lakes. Current methods are based on identification by light microscopy, which is laborious. An alternative is to identify species based on short DNA fragments and High-Throughput Sequencing (HTS). However a potential limitation is the incomplete coverage of species in reference barcode libraries. Usually these libraries are compiled by isolating cells, before culturing and sequencing them, which is tedious and often unsuccessful. Here we propose the use of rbcL sequences from environmental samples analysed by HTS. We set several criteria to ensure good sequence quality and correspondence with the target species observed in microscopy: the sequence needed to be abundant in the sample, and with no insertions nor deletions or stop codon, phylogenetic neighbour taxa had to correspond to neighbour taxonomic taxa expected from morphological observations. Four species from tropical rivers are given as examples, including one that is new to science.
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| 3. |
- Riaux-Gobin, C., et al.
(författare)
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New species in the marine diatom genus Olifantiella (Bacillariophyta, Biraphidineae) from Rodrigues Island (Western Indian Ocean)
- 2012
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Ingår i: Fottea. - 1802-5439. ; 12:2, s. 199-217
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Tidskriftsartikel (refereegranskat)abstract
- Olifantiella RIAUX-GOBIN et COMPERE (Bacillariophyta, Biraphidineae), a monospecific diatom genus from coral reef environments in Reunion Island (Western Indian Ocean), was collected from Rodrigues Island (easterly island of the Mascarene archipelago) in 2007. Several taxa with the external characteristics of Olifantiella were observed in shallow lagoon sediments. The external opening connected to the internal process is easily identified in each taxon. The processes are on the same or opposite side of the frustule, depending on the taxon. Several taxa are present: I) Olifantiella cf. mascarenica RIAUX-GOBIN et COMPERE, 2) O. rodriguensis sp. nov., with an elongate shape and a double buciniportula, 3) O. gorandiana sp. nov., with a naviculoid shape and a complex buciniportula composed of two flattened tubes, that do not protrude, flanked by two small satellites, and 4) O. pilosella sp. nov., O. paucistriata sp. nov. and O. pseudobiremis sp. nov., which are only described from external views. The scarcity and minute size of the taxa necessitated the use of scanning electron microscopy (SEM) to examine and distinguish them accurately. Some LM observations were made when possible. During previous tropical marine surveys, the genus Olifantiella may have been overlooked or misidentified, due to its small size, fragile frustules, and often naviculoid shape. We discuss the morphological diversity of the genus, e.g. the frustule and buciniportula shape and structure, and propose a formal emended description of the genus Olifantiella.
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| 4. |
- Riaux-Gobin, C., et al.
(författare)
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Planothidium juandenovense sp. nov. (Bacillariophyta) from Juan de Nova (Scattered Islands, Mozambique Channel) and other tropical environments: A new addition to the Planothidium delicatulum complex
- 2018
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Ingår i: Fottea. - : Palacky University Olomouc. - 1802-5439 .- 1805-4927. ; 18:1, s. 106-119
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Tidskriftsartikel (refereegranskat)abstract
- Planothidium juandenovense sp. nov. (Bacillariophyta) is described from the marine tropical environments of Juan de Nova I. (Mozambique Channel), Rodrigues I. (Mascarene Archipelago) and from Guam (Northern Mariana Is., Pacific). This small and relatively rare taxon has short multiseriate striae on the sternum valve (SV), hooked raphe valve (RV) terminal raphe endings and no SV cavum or hoof-shaped area. This taxon has similarities with Planothidium delicatulum (Kütz.) Round et Bukht. and Planothidium septentrionale (Østrup) Round et Bukht. ex Rumrich et al., but also differences: e.g. a relatively narrow and rhombic SV sternum, void of areolae, with vestigial radiate structures and an uninterrupted marginal SV elevated crest or ‘crista marginalis’. P. juandenovense sp. nov. is compared to some other Achnanthales with short SV striae. Cocconeis quarnerensis var. lanceolata Jurilj and Planothidium quarnerense f. rhombica (Giffen) comb. nov. may be close to our new taxon. © Czech Phycological Society (2018).
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| 5. |
- Schagerl, Michael, et al.
(författare)
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Algal communities of Kenyan soda lakes with a special focus on Arthrospira fusiformis
- 2015
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Ingår i: Fottea. - : Palacky University Olomouc. - 1802-5439 .- 1805-4927. ; 15:2, s. 245-257
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Tidskriftsartikel (refereegranskat)abstract
- Soda lakes are simple in biodiversity, but due to their highly stochastic environmental dynamics unexpected shifts in species composition do occur. We studied key drivers for structuring phytoplankton communities and identified variables significantly influencing changes of Arthrospira fusiformis abundance in the Kenyan soda lakes, Nakuru and Bogoria. In both lakes, Arthrospira fusiformis dominated algal biomass, but in Nakuru, crashes of this taxon were recorded. The three variables sodium, pH and dry mass significantly contributed to the phytoplankton taxa pattern. Arthrospira was absent at highest turbidity and salinity levels, being outcompeted by the small, single-celled chlorophyte Picocystis salinarium. Picoplankton was in general connected to higher pH values and tended to occur anti-cyclic to Arthrospira. Overall, the abundance of A. fusiformis was influenced by the boundaries of habitat suitability, light penetration, grazers and cyanophages attacks.
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| 6. |
- Szabó-Taylor, Katalin É., et al.
(författare)
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Composition and dynamics of microeukaryote communities in the River Danube
- 2010
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Ingår i: Fottea. - 1802-5439. ; 10:1, s. 99-113
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Tidskriftsartikel (refereegranskat)abstract
- The diversity of microeukaryote communities inhabiting rivers is still poorly known. Here, we have analyzed the periphytic and planktonic microeukaryote communities present in one section of the River Danube by two different methods: 18S rRNA-based terminal restriction fragment length polymorphism with fragment sequencing and microscopical analysis of the phytoplankton and periphyton. Both data sets were then related to environmental variables. Molecular fingerprinting revealed diverse communities with fluctuating composition, with the majority of sequences affiliated to the groups Bacillariophyta, Synurophyceae and Chlorophyceae. This was in accordance with microscopical data. The total number of detected T-RFs during the study period was 145, with more than half of the T-RFs being restricted to either plankton or periphyton. This suggests that the likely different natural selection regimes experienced by microeukaryotes in these two environments may promote the presence of different lineages in each of them. Significant correlations were found between phytoplankton chlorophyll a content, phosphorus content, temperature, and the T RFLP pattern of the planktonic microeukaryotic community, suggesting that the former environmental factors are especially important in structuring the planktonic microeukaryote communities in the River Danube. These data, together with earlier studies suggest that molecular methods are an invaluable addition in pursuit of the better understanding of the diversity and fluctuation of freshwater microeukaryotic communities.
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