I. Becerra-Absalón, J. Johansen, Karina Osorio-Santos, G. Montejano
Two isolates of Oculatella from biological soil crusts in the arid and semi-arid tropical upland region of Mexico were characterized using a polyphasic approach which included morphology, ecology, 16S rRNA and 16S-23S ITS phylogenetic analysis, percent identity of 16S rRNA gene sequence, percent dissimilarity of 16S-23S ITS sequence, and secondary structure of conserved ITS domains. The two species shared the generic synapomorphy of a reddish granule at the tip of mature apical cells, and possessed a single ribosomal operon with both tRNA genes (tRNAIle and tRNAAla) based upon our analysis and the analysis of the other species in the genus. After characterization, the strains were compared with 10 previously described and similarly characterized species in the genus, and based upon the evidence obtained, the strains were described as two new species, O. dilatativagina and O. leona. O. dilatativagina has an extensively widened sheath, and thus is morphologically separated from all other taxa described thus far. O. leona is morphologically highly similar to soil species found in North and South America, and should be considered a cryptic species among these taxa. The recently developed criterion for species recognition using percent dissimilarity among ITS gene sequences in orthologous ribosomal operons was found to be effective in separating cryptic species of Oculatella, and has consistently been useful and sufficient for separation of closely related species in other cyanobacterial genera.
{"title":"Two new Oculatella (Oculatellaceae, Cyanobacteria) species in soil crusts from tropical semi-arid uplands of México","authors":"I. Becerra-Absalón, J. Johansen, Karina Osorio-Santos, G. Montejano","doi":"10.5507/fot.2020.010","DOIUrl":"https://doi.org/10.5507/fot.2020.010","url":null,"abstract":"Two isolates of Oculatella from biological soil crusts in the arid and semi-arid tropical upland region of Mexico were characterized using a polyphasic approach which included morphology, ecology, 16S rRNA and 16S-23S ITS phylogenetic analysis, percent identity of 16S rRNA gene sequence, percent dissimilarity of 16S-23S ITS sequence, and secondary structure of conserved ITS domains. The two species shared the generic synapomorphy of a reddish granule at the tip of mature apical cells, and possessed a single ribosomal operon with both tRNA genes (tRNAIle and tRNAAla) based upon our analysis and the analysis of the other species in the genus. After characterization, the strains were compared with 10 previously described and similarly characterized species in the genus, and based upon the evidence obtained, the strains were described as two new species, O. dilatativagina and O. leona. O. dilatativagina has an extensively widened sheath, and thus is morphologically separated from all other taxa described thus far. O. leona is morphologically highly similar to soil species found in North and South America, and should be considered a cryptic species among these taxa. The recently developed criterion for species recognition using percent dissimilarity among ITS gene sequences in orthologous ribosomal operons was found to be effective in separating cryptic species of Oculatella, and has consistently been useful and sufficient for separation of closely related species in other cyanobacterial genera.","PeriodicalId":55149,"journal":{"name":"Fottea","volume":"20 1","pages":"160-170"},"PeriodicalIF":2.2,"publicationDate":"2020-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49003558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Radhakrishnan, S. Das, Vikas Kumar, J. Kociolek, B. Karthick
A new freshwater diatom species, Gomphonema adhikarii sp. nov., is described from a small road-side pool from the alpine region of Arunachal Pradesh, Eastern Himalayas, India. Detailed valve morphological features, based on both light and scanning electron microscopy, is presented and this taxon is compared with similar species. Gomphonema adhikarii has a distinct asymmetry about the apical axis and slightly bent foot pole area. The outline of the valve is slightly undulate, the valve centre is swollen and both apices are broadly rounded. This new species described from the Eastern Himalayas supports the idea of the area being rich in biodiversity, even with respect to the freshwater diatom flora.
{"title":"A new freshwater Gomphonema Ehrenberg (Bacillariophyta) species from Eastern Himalayas, India","authors":"C. Radhakrishnan, S. Das, Vikas Kumar, J. Kociolek, B. Karthick","doi":"10.5507/fot.2020.003","DOIUrl":"https://doi.org/10.5507/fot.2020.003","url":null,"abstract":"A new freshwater diatom species, Gomphonema adhikarii sp. nov., is described from a small road-side pool from the alpine region of Arunachal Pradesh, Eastern Himalayas, India. Detailed valve morphological features, based on both light and scanning electron microscopy, is presented and this taxon is compared with similar species. Gomphonema adhikarii has a distinct asymmetry about the apical axis and slightly bent foot pole area. The outline of the valve is slightly undulate, the valve centre is swollen and both apices are broadly rounded. This new species described from the Eastern Himalayas supports the idea of the area being rich in biodiversity, even with respect to the freshwater diatom flora.","PeriodicalId":55149,"journal":{"name":"Fottea","volume":"20 1","pages":"128-136"},"PeriodicalIF":2.2,"publicationDate":"2020-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44909912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During a survey of the diatom flora attached to carapaces of loggerhead sea turtles (Caretta caretta) from the Adriatic Sea, a large population of an unknown marine achnanthoid species was observed that could not be assigned to any of the currently described monoraphid diatom genera. Detailed morphological analysis based on scanning electron microscopy observations and comparison with a large number of monoraphid genera such as Madinithidium, Scalariella, Kolbesia and Karayevia, resulted in the description of the new benthic marine genus Majewskaea gen. nov. with the newly described Majewskaea istriaca sp. nov. as generitype. The new genus is characterized by a sternum valve showing a clear recurving ridge surrounding the entire valve margin, the presence of macroareolae closed internally by perforated hymenes, separated by a longitudinal hyaline area, a well-developed sternum and vestigial raphe slits. The raphe valve has a simple straight raphe with bent terminal fissures, a very fine striation pattern composed of macroareolae cut in two by a longitudinal hyaline zone, and a very shallow mantle. The new genus is illustrated using both LM and SEM observations and compared with other resembling marine and brackish Planothidium monoraphid species.
在对亚得里亚海红海龟（Caretta careta）甲壳上附着的硅藻植物群进行调查期间，观察到大量未知的海洋无刺硅藻物种，这些物种无法被分配到目前描述的任何一个广场形硅藻属。基于扫描电子显微镜观察的详细形态分析，并与大量的广场菌属（如Madinithidium、Scalariella、Kolbesia和Karayevia）进行比较，得出了新的底栖海洋属Majewskaea gen.nov.的描述，新描述的Majewska ea istriaca sp.nov.为genetype。新属的特征是胸骨瓣在整个瓣缘周围有一个清晰的下弯脊，大乳晕由穿孔的处女膜内部封闭，由纵向透明区分隔，胸骨发育良好，中缝狭缝残留。中缝瓣有一个简单的直中缝，带有弯曲的末端裂隙，一个由被纵向透明带切成两半的大晕组成的非常精细的条纹图案，以及一个非常浅的地幔。利用LM和SEM观察对该新属进行了说明，并将其与其他类似海洋和半咸水Planothidium monophilid物种进行了比较。
{"title":"Majewskaea gen. nov. (Bacillariophyta), a new marine benthic diatom genus from the Adriatic Sea","authors":"B. Vijver, K. Robert, A. Witkowski, Sunčica Bosak","doi":"10.5507/fot.2020.001","DOIUrl":"https://doi.org/10.5507/fot.2020.001","url":null,"abstract":"During a survey of the diatom flora attached to carapaces of loggerhead sea turtles (Caretta caretta) from the Adriatic Sea, a large population of an unknown marine achnanthoid species was observed that could not be assigned to any of the currently described monoraphid diatom genera. Detailed morphological analysis based on scanning electron microscopy observations and comparison with a large number of monoraphid genera such as Madinithidium, Scalariella, Kolbesia and Karayevia, resulted in the description of the new benthic marine genus Majewskaea gen. nov. with the newly described Majewskaea istriaca sp. nov. as generitype. The new genus is characterized by a sternum valve showing a clear recurving ridge surrounding the entire valve margin, the presence of macroareolae closed internally by perforated hymenes, separated by a longitudinal hyaline area, a well-developed sternum and vestigial raphe slits. The raphe valve has a simple straight raphe with bent terminal fissures, a very fine striation pattern composed of macroareolae cut in two by a longitudinal hyaline zone, and a very shallow mantle. The new genus is illustrated using both LM and SEM observations and compared with other resembling marine and brackish Planothidium monoraphid species.","PeriodicalId":55149,"journal":{"name":"Fottea","volume":"20 1","pages":"112-120"},"PeriodicalIF":2.2,"publicationDate":"2020-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44213582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Three new freshwater diatoms are described from China's Yunnan Plateau region in sediments from Lake Fuxian. Navicula australasiatica nov. sp., Navicula perangustissima nov. spec., and Navicula turriformis nov. spec. were identified from light and scanning electron micrographs. All new species are sufficiently different from other similar species based on valve outline, shape of the axial and center areas, and stria density. These three new species are all observed in surficial sediment from Lake Fuxian and compared to morphologically similar species from the genus Navicula.
{"title":"Three new Navicula (Bacillariophyta) species from an oligotrophic, deep lake, China","authors":"Yanling Li, Mengna Liao, D. Metzeltin","doi":"10.5507/fot.2020.002","DOIUrl":"https://doi.org/10.5507/fot.2020.002","url":null,"abstract":"Three new freshwater diatoms are described from China's Yunnan Plateau region in sediments from Lake Fuxian. Navicula australasiatica nov. sp., Navicula perangustissima nov. spec., and Navicula turriformis nov. spec. were identified from light and scanning electron micrographs. All new species are sufficiently different from other similar species based on valve outline, shape of the axial and center areas, and stria density. These three new species are all observed in surficial sediment from Lake Fuxian and compared to morphologically similar species from the genus Navicula.","PeriodicalId":55149,"journal":{"name":"Fottea","volume":"20 1","pages":"121-127"},"PeriodicalIF":2.2,"publicationDate":"2020-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44239641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A novel diatom species belonging to the genus Nagumoea is described based on detailed light and scanning electron microscopy observations. The new taxon was found abundantly in several samples collected from seagrass on the southernmost coasts of Mozambique, Southern Africa. While the new species shows characters (e.g. scalariform valvocopula, fibulae of complex shape and structure) consistent with the genus description, it differs distinctly from currently known members of Nagumoea. Differences include generally larger (7-29 µm) and more slender (1.0-1.5 µm) valves with acutely rounded apices and 4-5 areolae per stria, a doubly-perforated valvocopula, and the last-formed copula with a highly regular serrated margin. Based on the current knowledge and understanding of the diatom morphology and phylogeny, Anaulus vallus Nikolaev, previously included within the genus Denticula, is transferred to the genus Nagumoea. This brings the current number of the genus members to five. Ecological preferences of Nagumoea are briefly discussed.
{"title":"Nagumoea serrata, a new diatom species (Bacillariophyceae) found on seagrass from the south-eastern coast of Africa (Indian Ocean)","authors":"R. Majewska, B. Vijver","doi":"10.5507/fot.2019.019","DOIUrl":"https://doi.org/10.5507/fot.2019.019","url":null,"abstract":"A novel diatom species belonging to the genus Nagumoea is described based on detailed light and scanning electron microscopy observations. The new taxon was found abundantly in several samples collected from seagrass on the southernmost coasts of Mozambique, Southern Africa. While the new species shows characters (e.g. scalariform valvocopula, fibulae of complex shape and structure) consistent with the genus description, it differs distinctly from currently known members of Nagumoea. Differences include generally larger (7-29 µm) and more slender (1.0-1.5 µm) valves with acutely rounded apices and 4-5 areolae per stria, a doubly-perforated valvocopula, and the last-formed copula with a highly regular serrated margin. Based on the current knowledge and understanding of the diatom morphology and phylogeny, Anaulus vallus Nikolaev, previously included within the genus Denticula, is transferred to the genus Nagumoea. This brings the current number of the genus members to five. Ecological preferences of Nagumoea are briefly discussed.","PeriodicalId":55149,"journal":{"name":"Fottea","volume":"20 1","pages":"98-103"},"PeriodicalIF":2.2,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49085213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saber, A bAbdullah, Ehab F. El-Belely, A. El-Refaey, A. El-Gamal, S. Blanco, M. Cantonati
During a recent floristic-taxonomic study on the algal flora, including diatoms, from the estuary of the Damietta Branch of the Nile in Egypt, an interesting epilithic diatom species belonging to the genus Seminavis (Naviculaceae) was collected and investigated using both light and scanning electron microscopy. This new diatom species shares morphologically some taxonomic diagnostic features with other related taxa such as S. insignis, S. robusta, and S. ventricosa. However, it still differs by having ventral central striae that are shorter and more or less straight in the middle of the smaller frustules to be clearly radiate in the larger ones and then become geniculate and only radiate near the poles, the central raphe endings are externally more distantly spaced than in the similar species, the elongate central nodule is internally less prominent, and the areola density is much denser. Therefore, we here describe it as Seminavis aegyptiaca sp. nov. Hydrochemical analyses revealed that S. aegyptiaca commonly inhabits typical marine, with a weak tendency towards brackish water, habitats. It was found to be tolerant to meso-eutrophic, nutrient-enriched conditions, based on the data available on seasonal concentrations of N and P compounds. These findings not only contribute to the inventory of Egyptian diatoms, but also increase our understanding of the autecology and distribution of this relatively poorly-known diatom genus.
{"title":"Seminavis aegyptiaca sp. nov., a new amphoroid diatom species from estuary epilithon of the River-Nile Damietta Branch, Egypt","authors":"Saber, A bAbdullah, Ehab F. El-Belely, A. El-Refaey, A. El-Gamal, S. Blanco, M. Cantonati","doi":"10.5507/fot.2019.015","DOIUrl":"https://doi.org/10.5507/fot.2019.015","url":null,"abstract":"During a recent floristic-taxonomic study on the algal flora, including diatoms, from the estuary of the Damietta Branch of the Nile in Egypt, an interesting epilithic diatom species belonging to the genus Seminavis (Naviculaceae) was collected and investigated using both light and scanning electron microscopy. This new diatom species shares morphologically some taxonomic diagnostic features with other related taxa such as S. insignis, S. robusta, and S. ventricosa. However, it still differs by having ventral central striae that are shorter and more or less straight in the middle of the smaller frustules to be clearly radiate in the larger ones and then become geniculate and only radiate near the poles, the central raphe endings are externally more distantly spaced than in the similar species, the elongate central nodule is internally less prominent, and the areola density is much denser. Therefore, we here describe it as Seminavis aegyptiaca sp. nov. Hydrochemical analyses revealed that S. aegyptiaca commonly inhabits typical marine, with a weak tendency towards brackish water, habitats. It was found to be tolerant to meso-eutrophic, nutrient-enriched conditions, based on the data available on seasonal concentrations of N and P compounds. These findings not only contribute to the inventory of Egyptian diatoms, but also increase our understanding of the autecology and distribution of this relatively poorly-known diatom genus.","PeriodicalId":55149,"journal":{"name":"Fottea","volume":"20 1","pages":"49-57"},"PeriodicalIF":2.2,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42295803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Bąk, Dariusz Halabowski, A. Kryk, I. Lewin, A. Sowa
The composition of the diatom assemblages was analysed in four rivers of Upper Silesia, Poland in 2017. The diatom assemblages studied were found to reflect anthropogenic salinization caused by mining activities. The assemblages in those rivers characterised by the highest salinity (Bolina and Mleczna) showed a relatively low taxonomic richness. The diatom assemblages were dominated by species typical of brackish or marine waters. The rivers with a minimal or weak anthropogenic impact (Centuria and Mitrega) supported taxonomically richer diatom assemblages typical of mid-altitude siliceous or calcareous streams (respectively), that have a fine particulate substratum. The presence of a new species, Planothidium nanum sp. nov., was revealed. The new species shows a unique set of morphological characters, including small size; its elliptical outline as well as very widely-spaced central striae on the sternum valve (sinus) and widely-spaced central striae on the raphe valve allow to separate it from other similar Planothidium.
{"title":"Mining salinisation of rivers: its impact on diatom (Bacillariophyta) assemblages","authors":"M. Bąk, Dariusz Halabowski, A. Kryk, I. Lewin, A. Sowa","doi":"10.5507/fot.2019.010","DOIUrl":"https://doi.org/10.5507/fot.2019.010","url":null,"abstract":"The composition of the diatom assemblages was analysed in four rivers of Upper Silesia, Poland in 2017. The diatom assemblages studied were found to reflect anthropogenic salinization caused by mining activities. The assemblages in those rivers characterised by the highest salinity (Bolina and Mleczna) showed a relatively low taxonomic richness. The diatom assemblages were dominated by species typical of brackish or marine waters. The rivers with a minimal or weak anthropogenic impact (Centuria and Mitrega) supported taxonomically richer diatom assemblages typical of mid-altitude siliceous or calcareous streams (respectively), that have a fine particulate substratum. The presence of a new species, Planothidium nanum sp. nov., was revealed. The new species shows a unique set of morphological characters, including small size; its elliptical outline as well as very widely-spaced central striae on the sternum valve (sinus) and widely-spaced central striae on the raphe valve allow to separate it from other similar Planothidium.","PeriodicalId":55149,"journal":{"name":"Fottea","volume":"20 1","pages":"1-16"},"PeriodicalIF":2.2,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45259322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Kulikovskiy, A. Glushchenko, S. Genkal, I. Kuznetsova, J. Kociolek
A new monoraphid diatom genus, Platebaikalia gen. nov., was described based on a detailed morphological investigation using light and scanning electron microscopy. Previously Platessa elegans Kulikovskiy et Lange-Bertalot was described from ancient Lake Baikal, and this species serves as the generitype for the newly-described genus. Platebaikalia elegans is a rare taxon found in the deeper parts of Lake Baikal. Platebaikalia elegans is characterized by having multiseriate striae on the raphe valves with biseriate striae on the rapheless valves, though in some specimens a short third row of areolae may be present in some striae. Morphology of striae is helpful to distinguish the genus Platebaikalia from Platessa and other monoraphid genera. Other morphological features that differentiate our new genus from other monoraphid taxa are discussed. We review the morphological data on Platessa species, and based on these data can recognize eight groups of taxa in the genus. Our analysis shows that Platessa as currently circumscribed may contain groups of species that are quite different from one another morphologically, and possibly includes taxa that could be recognized as different at the genus level. A few new combinations are suggested when taxa from the genus Platessa transferred to genera Psammothidium and Planothidium. Some problems of taxonomy of monoraphid taxa are discussed and we believe that taxonomy of this group of diatoms is in need of special attention in future.
根据光镜和扫描电子显微镜的详细形态学研究，描述了一个新的广场形硅藻属Platebaikalia gen.nov。以前，古贝加尔湖曾描述过秀丽隐杆线虫Kulikovskiy et Lange Bertalot，该物种是新描述的属的属。Platebaikalia elegans是在贝加尔湖较深处发现的一个罕见的分类单元。Platebaikalia elegans的特征是在中缝瓣上有多条纹，在无中缝瓣处有双列条纹，尽管在一些标本中，在一些条纹中可能存在短的第三排乳晕。纹的形态有助于区分Platebaikalia属、Platessa属和其他广场花属。我们还讨论了将我们的新属与其他广场菌分类群区分开来的其他形态特征。我们回顾了Platessa物种的形态学数据，并基于这些数据可以识别该属的八组分类群。我们的分析表明，目前限定的Platessa可能包含在形态上彼此截然不同的物种群，并且可能包括在属水平上可以被识别为不同的分类群。当Platessa属的分类群转移到Psamuthidium属和Planothidium属时，提出了一些新的组合。讨论了广场菌分类群分类学中的一些问题，认为这类硅藻的分类在今后需要特别注意。
{"title":"Platebaikalia - a new monoraphid diatom genus from ancient Lake Baikal with comments on the genus Platessa","authors":"M. Kulikovskiy, A. Glushchenko, S. Genkal, I. Kuznetsova, J. Kociolek","doi":"10.5507/fot.2019.014","DOIUrl":"https://doi.org/10.5507/fot.2019.014","url":null,"abstract":"A new monoraphid diatom genus, Platebaikalia gen. nov., was described based on a detailed morphological investigation using light and scanning electron microscopy. Previously Platessa elegans Kulikovskiy et Lange-Bertalot was described from ancient Lake Baikal, and this species serves as the generitype for the newly-described genus. Platebaikalia elegans is a rare taxon found in the deeper parts of Lake Baikal. Platebaikalia elegans is characterized by having multiseriate striae on the raphe valves with biseriate striae on the rapheless valves, though in some specimens a short third row of areolae may be present in some striae. Morphology of striae is helpful to distinguish the genus Platebaikalia from Platessa and other monoraphid genera. Other morphological features that differentiate our new genus from other monoraphid taxa are discussed. We review the morphological data on Platessa species, and based on these data can recognize eight groups of taxa in the genus. Our analysis shows that Platessa as currently circumscribed may contain groups of species that are quite different from one another morphologically, and possibly includes taxa that could be recognized as different at the genus level. A few new combinations are suggested when taxa from the genus Platessa transferred to genera Psammothidium and Planothidium. Some problems of taxonomy of monoraphid taxa are discussed and we believe that taxonomy of this group of diatoms is in need of special attention in future.","PeriodicalId":55149,"journal":{"name":"Fottea","volume":"20 1","pages":"58-67"},"PeriodicalIF":2.2,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47847057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
René Le Cohu, H. LANGE-BERTALOT, Bart Van de Viver, L. Tudesque
Delicatophycus costei (Lange-Bertalot et Moser) Wynne, Cymbella bourrellyi Maillard, Cymbella latarea Maillard and Cymbella pernodensis Maillard are endemic to New Caledonia and show uncommon morphological features compared to the "sensu stricto" definition of their respective genus. Delicatophycus costei was described based on light microscopy and scanning electron microscopy (SEM) observations, confirming the generic LM diagnosis. However, the external view in SEM is atypical as both valve face and mantle are covered by longitudinal ribs, overlaying part of the zig-zag striae, generally accepted as the determinant generic feature. The three species of Cymbella have both apical pore fields and "stigmata". However, they show some specific morphological features compared to the more classically shaped Cymbella species. Cymbella bourrellyi has a narrow hyaline area on the valve face and the areolae are bordered internally by small outgrowths. Cymbella pernodensis is distinguished by internal biseriate striae. The internal morphology of Cymbella latarea is characteristic in having typical biseriate striae and bisected apical pore fields. In these three species, internally, the stigmata are continuous with the striae and appear as simple and only weakly separated structures at the end of the striae. The three species are also characterized by differences in the number of areola rows per stria externally and internally.
{"title":"Analysis and critical evaluation of structural features in four Cymbellaceae taxa from New Caledonia","authors":"René Le Cohu, H. LANGE-BERTALOT, Bart Van de Viver, L. Tudesque","doi":"10.5507/fot.2019.017","DOIUrl":"https://doi.org/10.5507/fot.2019.017","url":null,"abstract":"Delicatophycus costei (Lange-Bertalot et Moser) Wynne, Cymbella bourrellyi Maillard, Cymbella latarea Maillard and Cymbella pernodensis Maillard are endemic to New Caledonia and show uncommon morphological features compared to the \"sensu stricto\" definition of their respective genus. Delicatophycus costei was described based on light microscopy and scanning electron microscopy (SEM) observations, confirming the generic LM diagnosis. However, the external view in SEM is atypical as both valve face and mantle are covered by longitudinal ribs, overlaying part of the zig-zag striae, generally accepted as the determinant generic feature. The three species of Cymbella have both apical pore fields and \"stigmata\". However, they show some specific morphological features compared to the more classically shaped Cymbella species. Cymbella bourrellyi has a narrow hyaline area on the valve face and the areolae are bordered internally by small outgrowths. Cymbella pernodensis is distinguished by internal biseriate striae. The internal morphology of Cymbella latarea is characteristic in having typical biseriate striae and bisected apical pore fields. In these three species, internally, the stigmata are continuous with the striae and appear as simple and only weakly separated structures at the end of the striae. The three species are also characterized by differences in the number of areola rows per stria externally and internally.","PeriodicalId":55149,"journal":{"name":"Fottea","volume":"20 1","pages":"75-85"},"PeriodicalIF":2.2,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48128342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Motto: "I consider the human endeavour to discover new processes and regularities in nature, completed by requirement and satisfaction in logical arrangement of discovered facts into the objective and regular order, as a main stimulus of the noble evolution of the human society." - Albert Einstein. The problem of identification and evaluation of new described cyanobacterial taxa, particularly of the genera established after molecular sequencing, is discussed. Numerous new taxonomic units were defined according to molecular analyses in the last 20 years, but their later identification by biological community (particularly by ecologists) is often hardly possible. The molecular sequencing and evaluation must be surely a basis of the modern and future taxonomic classification, but the application of polyphasic approach to the definition of single taxa and enabling the orientation and later recognition of all described taxonomic units is quite necessary and inevitable.
{"title":"Quo vadis, taxonomy of cyanobacteria (2019)","authors":"J. Komárek","doi":"10.5507/fot.2019.020","DOIUrl":"https://doi.org/10.5507/fot.2019.020","url":null,"abstract":"Motto: \"I consider the human endeavour to discover new processes and regularities in nature, completed by requirement and satisfaction in logical arrangement of discovered facts into the objective and regular order, as a main stimulus of the noble evolution of the human society.\" - Albert Einstein. The problem of identification and evaluation of new described cyanobacterial taxa, particularly of the genera established after molecular sequencing, is discussed. Numerous new taxonomic units were defined according to molecular analyses in the last 20 years, but their later identification by biological community (particularly by ecologists) is often hardly possible. The molecular sequencing and evaluation must be surely a basis of the modern and future taxonomic classification, but the application of polyphasic approach to the definition of single taxa and enabling the orientation and later recognition of all described taxonomic units is quite necessary and inevitable.","PeriodicalId":55149,"journal":{"name":"Fottea","volume":"20 1","pages":"104-110"},"PeriodicalIF":2.2,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42276900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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