228 research outputs found
FIGURES 9–14. Stauroneis lacuspowaiensis Wadmare & B in Revisiting two Stauroneis Ehrenberg (Bacillariophyta) from H. P. Gandhi's Diatom collection: Notes on Ultrastructure, Types and Nomenclature
No full textFIGURES 9–14. Stauroneis lacuspowaiensis Wadmare & B.Karthick nom. nov., stat. nov., SEM, external valve views. 9, 10. External views of an entire valve. 11, 13. Terminal raphe fissures continuing on mantle. 12. Stauros with straight central raphe ends. 14. Irregularly placed areolae (double arrowheads). Scale bars = 4 µm (Figs 9, 10, 12); 1 µm (Figs 11, 13, 14).Published as part of Wadmare, Neha & Karthick, Balasubramanian, 2022, Revisiting two Stauroneis Ehrenberg (Bacillariophyta) from H. P. Gandhi's Diatom collection: Notes on Ultrastructure, Types and Nomenclature, pp. 42-52 in Phytotaxa 555 (1) on page 45, DOI: 10.11646/phytotaxa.555.1.3, http://zenodo.org/record/687561
FIGURES 19–31. Stauroneis dharwarensis Wadmare & B in Revisiting two Stauroneis Ehrenberg (Bacillariophyta) from H. P. Gandhi's Diatom collection: Notes on Ultrastructure, Types and Nomenclature
No full textFIGURES 19–31. Stauroneis dharwarensis Wadmare & B.Karthick nom. nov., stat. nov., 19. Original illustration of Gandhi (1959a: 104, 105, Fig. 25). 20–31. Light micrographs (DIC) from the type material (AHMA Sr 48), Fig. 24 represents the lectotype. Scale bar = 10 µm.Published as part of Wadmare, Neha & Karthick, Balasubramanian, 2022, Revisiting two Stauroneis Ehrenberg (Bacillariophyta) from H. P. Gandhi's Diatom collection: Notes on Ultrastructure, Types and Nomenclature, pp. 42-52 in Phytotaxa 555 (1) on page 47, DOI: 10.11646/phytotaxa.555.1.3, http://zenodo.org/record/687561
FIGURES 37–41. Stauroneis dharwarensis Wadmare & B in Revisiting two Stauroneis Ehrenberg (Bacillariophyta) from H. P. Gandhi's Diatom collection: Notes on Ultrastructure, Types and Nomenclature
No full textFIGURES 37–41. Stauroneis dharwarensis Wadmare & B.Karthick nom. nov., stat. nov., SEM, internal valve views. 37, 38. Internal views of an entire valve. 37, 39. Apices showing terminal raphe fissures as helictoglossae. 40. Stauros thick bearing deflected central raphe ends. 39–41. Areolae with hymen layer. Scale bars = 4 µm (Figs 37–41).Published as part of Wadmare, Neha & Karthick, Balasubramanian, 2022, Revisiting two Stauroneis Ehrenberg (Bacillariophyta) from H. P. Gandhi's Diatom collection: Notes on Ultrastructure, Types and Nomenclature, pp. 42-52 in Phytotaxa 555 (1) on page 49, DOI: 10.11646/phytotaxa.555.1.3, http://zenodo.org/record/687561
FIGURES 1–8. Stauroneis lacuspowaiensis Wadmare & B in Revisiting two Stauroneis Ehrenberg (Bacillariophyta) from H. P. Gandhi's Diatom collection: Notes on Ultrastructure, Types and Nomenclature
No full textFIGURES 1–8. Stauroneis lacuspowaiensis Wadmare & B.Karthick nom. nov., stat. nov., 1. Original illustration of Gonzalves & Gandhi (1953: 256, fig. 92). 2–8. Light micrographs (DIC) from the type material (AHMA Sr 5), Fig. 4. represent the lectotype. 4. Irregularly punctate areolae (double arrowheads). 5. Valve with slight undulate sides (arrow). 7. Terminal raphe fissures with bifurcation (arrowhead). Scale bar = 10 µm.Published as part of Wadmare, Neha & Karthick, Balasubramanian, 2022, Revisiting two Stauroneis Ehrenberg (Bacillariophyta) from H. P. Gandhi's Diatom collection: Notes on Ultrastructure, Types and Nomenclature, pp. 42-52 in Phytotaxa 555 (1) on page 44, DOI: 10.11646/phytotaxa.555.1.3, http://zenodo.org/record/687561
Stauroneis dharwarensis Wadmare & B. Karthick 2022, nom. nov., stat. nov.
No full textStauroneis dharwarensis Wadmare & B.Karthick nom. nov., stat. nov. (Figs 19–41, Fig. 24 represents the lectotype) Basionym:— Stauroneis anceps f. indica in Gandhi 1959a, Ceylon Journal of Science (Biology Section), p. 104, 105, fig. 25 (here reproduced as Fig. 19). Type:— INDIA. Dharwar, Karnataka. Dharwar pools from paddy and millet fields watercourses during rains, 15°26’34.8” N, 74°54’43.2” E. Mr. H. P. Gandhi on 14 th August 1949 . Lectotype (designated here):—Agharkar Research Institute (AHMA) Gandhi Collection! Slide- Sr 48, here illustrated as Fig. 24. Description:—LM (Figs 19–31): Valves broadly lanceolate with constricted, subrostrate to rostrate apices. Length 32.0–64.0 µm, breadth 12.0–15.0 µm. Axial area narrow, widening at centre. Stauros bow-tie shaped, widening towards valve margin. Raphe slightly coarse with straight central raphe ends, terminal raphe fissures unilaterally deflected. Striae strongly radial punctate, 17–19/10 µm. Areolae punctate to transapically elongated, discernible in LM. (n= 36). SEM (Figs 32–41): Externally (Figs 32–36), valves linear-lanceolate with axial area narrow throughout but wider at centre (Figs 32, 36). Central raphe ends tear-drop shaped (Figs 32, 33). Terminal raphe fissures continuing onto mantle (Figs 34, 35). Striae uniseriate, composed of transapically elongated areolae, 24–28 in 10 µm (Figs 33–35). Internally (Figs 37–41), stauros broad, thickened and expanded (Figs 37, 38, 40). Central raphe ends slightly deflected, terminating onto well-developed stauros (Figs 38, 40). Terminal raphe fissures terminating onto helictoglossae (Figs 38, 39). Striae radiate, areolae with hymen occlusions (Figs 39–41). Remarks:—Valve dimensions of the specimens examined in the present study have a wider size range than H. P. Gandhi in the original description- length 54.0–58.0 µm; width 14.4 µm (see Table 2). This taxon is also observed in Sr 46, collected by H. P. Gandhi from the same site at the same time and date as Sr 48. Etymology:—The specific epithet “ dharwarensis ” refers to the type locality Mugad, Dharwar district, Karnataka, where H. P. Gandhi originally collected the sample.Published as part of Wadmare, Neha & Karthick, Balasubramanian, 2022, Revisiting two Stauroneis Ehrenberg (Bacillariophyta) from H. P. Gandhi's Diatom collection: Notes on Ultrastructure, Types and Nomenclature, pp. 42-52 in Phytotaxa 555 (1) on pages 47-48, DOI: 10.11646/phytotaxa.555.1.3, http://zenodo.org/record/687561
Stauroneis lacuspowaiensis Wadmare & B. Karthick 2022, nom. nov., stat. nov.
No full textStauroneis lacuspowaiensis Wadmare & B.Karthick nom. nov., stat. nov. (Figs 1–18, Fig. 4 represents the lectotype) Basionym: — Stauroneis phoenicenteron f. capitata in Gonzalves & Gandhi 1953, The Journal of Indian Botanical Societ y, p. 256, fig. 92 (here reproduced as Fig. 1) Heterotypic synonym: — Stauroneis nobilis f. capitata H.Kobayasi (in Kobayasi & Ando 1977) Type:— INDIA. Mumbai (then Bombay), Maharashtra. Powai Lake pavements having encrustations with dead vegetable matter, 19°7’37.2” N, 72°54’14.4” E, Mr. H. P. Gandhi on 6 th March 1945 . Lectotype (designated here):—Agharkar Research Institute (AHMA) Gandhi Collection! Slide- Sr 5, here illustrated as Fig. 4. Description:—LM (Figs 1–8): Valves narrowly linear-lanceolate, having large, capitate apices with slight undulate sides (Fig. 5, arrow). Length 98.5–103.0 µm, breadth 16.5–18.0 µm. Axial area broad widening near centre. Stauros slightly broad, rectangular. Raphe thick with straight central raphe ends, and sickle-shaped terminal raphe fissures with bifurcation (Fig. 7, arrowhead). Striae parallel at centre and radiate towards apices, 18–23/10 µm. Areolae irregularly punctate (Fig. 4, double arrowheads), discernible in LM. (n= 21). SEM (Figs 9–18): Externally (Figs 9–14), central raphe ends terminating on stauros (Figs 9, 10, 12). Raphe filiform (Fig. 12). Terminal raphe fissures sickle-shaped, continuing onto mantle (Figs 11, 13). Striae uniseriate, composed of irregularly placed, transapically elongated, slit-like areolae (Fig. 14, double arrowheads). Internally (Figs 15–18), stauros small, thickened and elevated with tunnel gap (Figs 15, 17, arrowheads). Terminal raphe fissures terminating onto helictoglossae (Figs 15, 16, 18). Areolae rounded to transapically elongated, 16–20 in 10 µm (Fig. 17, double arrowheads). Remarks:—Valve dimensions of the specimens examined in the current study have a smaller size range than the dimensions given by H. P. Gandhi in the original description length 113.4–120.0 µm; width 21.6 µm (see Table 1). In addition, previous studies based on Gandhi’s material observed certain morphometry discrepancies (Karthick & Kociolek 2012, Kale et al. 2017). Etymology:—The specific epithet “ lacuspowaiensis ” refers to the type locality Powai Lake, Mumbai, where H. P. Gandhi originally collected the sample.Published as part of Wadmare, Neha & Karthick, Balasubramanian, 2022, Revisiting two Stauroneis Ehrenberg (Bacillariophyta) from H. P. Gandhi's Diatom collection: Notes on Ultrastructure, Types and Nomenclature, pp. 42-52 in Phytotaxa 555 (1) on page 44, DOI: 10.11646/phytotaxa.555.1.3, http://zenodo.org/record/687561
FIGURES 2–29 in A new species of Hippodonta Lange-Bertalot, Metzeltin & Witkowski (Bacillariophyceae, Naviculales) from the Western Ghats, India
No full textFIGURES 2–29. Hippodonta mudumalaiensis sp. nov., LM (DIC) from the type material (AHMA #1752). 2–29. Showing the valve variability of the population. Fig. 22 represents the holotype. Scale bar = 10μm.Published as part of Vigneshwaran, Anbukkarasu, Wadmare, Neha & Karthick, Balasubramanian, 2022, A new species of Hippodonta Lange-Bertalot, Metzeltin & Witkowski (Bacillariophyceae, Naviculales) from the Western Ghats, India, pp. 219-228 in Phytotaxa 558 (2) on page 222, DOI: 10.11646/phytotaxa.558.2.5, http://zenodo.org/record/700298
FIGURES 30–34 in A new species of Hippodonta Lange-Bertalot, Metzeltin & Witkowski (Bacillariophyceae, Naviculales) from the Western Ghats, India
No full textFIGURES 30–34. Hippodonta mudumalaiensis sp. nov., SEM from the type material (AHMA #1405), external views. 30, 31. Views of the entire valve. 32. Central area. 33, 34. Valve apices. Scale bars = 1 μm (Figs 30–34).Published as part of Vigneshwaran, Anbukkarasu, Wadmare, Neha & Karthick, Balasubramanian, 2022, A new species of Hippodonta Lange-Bertalot, Metzeltin & Witkowski (Bacillariophyceae, Naviculales) from the Western Ghats, India, pp. 219-228 in Phytotaxa 558 (2) on page 223, DOI: 10.11646/phytotaxa.558.2.5, http://zenodo.org/record/700298
A critical analysis of the type material and taxonomic revision of the Indian Stauroneis acuta complex (Bacillariophyta) with the separation of two new species
No full textAbstract: The identification of Stauroneis acuta W.Smith was problematic for diatom taxonomists worldwide and led to the assumption that it is a cosmopolitan species. In the nineteenth century, several infraspecific taxa of S. acuta were described as varieties and forms across continents. In India, H.P. Gandhi reported S. acuta and described S. acuta var. tenuis Gonzalves & H.P.Gandhi. The present study attempts to revise Gandhi's S. acuta complex using his collections. In addition, the Van Heurck diatom collection (BR, Meise Botanic Garden, Belgium) has multiple syntype materials of S. acuta and was examined to elucidate the original concept and taxonomy of S. acuta, as an aid for resolving the Indian taxa. The morphology and ultrastructural details were analysed employing light and scanning electron microscopy observations. Our analysis of the Indian S. acuta complex reveals one new species: Stauroneis chemburensis Wadmare & B.Karthick sp. nov. Stauroneis acuta var. tenuis is validated as Stauroneis acutopsis Wadmare & B.Karthick nom. nov. stat. nov. Both taxa S. chemburensis and S. acutopsis can be differentiated from S. acuta based on valve outline, valve dimensions, the structure of the proximal raphe endings, and striae density. The current observations addresses the lectotypification of S. acuta W.Smith, clarifies the typification of Gandhi's specimens and provides new information about the morphology of the species
Hippodonta mudumalaiensis A. Vigneshwaran & B. Karthick 2022, sp. nov.
No full textHippodonta mudumalaiensis A.Vigneshwaran & B.Karthick sp. nov. (Figs 2–39, Fig. 22 represents the holotype) Description:— LM (Figs 2–29): Cells solitary, valves narrow-lanceolate to rhombic-lanceolate with broadly rounded apices. Valve length 13.0–20.0 μm, width 5.0–6.2 μm (n=67). Axial area narrow-linear, tilted, slightly asymmetric to the apical axis. Central area broadened with short single striae, shorter striae present at any one side; Striae radiate near centre and parallel near apices; no fascia is formed. Raphe linear-filiform, weakly pronounced, small teardrop-shaped and closely spaced central endings. Distal ends of raphe discernible in LM, equally pronounced as central endings, teardrop-shaped. Raphe distal ends positioned before terminal area or weakly advancing into slightly curved towards valve side. Terminal area distinguishable in LM, narrow, lunate and cap-like. Striae coarse, evenly spaced throughout valve, weakly to moderately radiate in the middle, becoming parallel or weakly convergent towards ends, 10–12/10 μm. Lineolae not discernible in LM. SEM (Figs 30–39): Externally (Figs 30–34), valves with flat face and slightly convex central area (Figs 30–32). Axial area slightly asymmetric (Fig. 30). Proximal raphe endings strongly pronounced, teardrop-shaped and bent towards same side as distal ends (Figs 31, 32). Terminal pores of raphe distinct, advancing towards the terminal area and deflected towards one valve side (Figs 33, 34). Terminal septa clearly developed and bordered by semi circumpolar (Figs 33, 34). Slit-like elongated areolae positioned on apical valve mantle, 40–50 in 10 μm. Striae uniseriate throughout valve, simple apically elongated lineolate, 50–60/10 μm. Rarely near central area transapically elongated lineolate areolae (Fig. 32). Striae in the central area clearly shortened, one side longer than the other side (Figs 30, 32). Prominent hyaline area present throughout the valve mantle (Fig. 31). Internally (Figs 35–39), striae placed in shallow linear depressions. Areolae covered by hymens. Central raphe endings simple, linear and gradually disappear (Fig. 38). Small wedge-shaped hyaline area present at centre. Distal raphe endings terminate on small defused helictoglossae (Figs 35, 36, 39). Terminal area internally prominent and bordered by hymenated linear depressions (Fig. 39). Type:— INDIA. Masinagudi, Nilgiris, Tamil Nadu. Stream, 11°33’14.8” N, 76°37’21.6” E, altitude 940 m asl, was collected by Mr. Kannan Govindarajan. (holotype AHMA! Slide #1752 = Fig. 22). Type material AHMA #1752. Habitat:— Epilithic, submerged stones in the stream. Water chemistry measurements includes pH of 7.35, nitrate (low range, NO 3 –) 0.03 mg ∙L- 1; dissolved oxygen (DO) 6.84 mg ∙L- 1; conductivity: 635 μS∙ cm-1; water temperature: 23.6 °C, total dissolved solids (TDS) 276 mg ∙L- 1. Etymology:— The specific epithet “ mudumalaiensis ” refers to the name of the location from which this new taxon is identified.Published as part of Vigneshwaran, Anbukkarasu, Wadmare, Neha & Karthick, Balasubramanian, 2022, A new species of Hippodonta Lange-Bertalot, Metzeltin & Witkowski (Bacillariophyceae, Naviculales) from the Western Ghats, India, pp. 219-228 in Phytotaxa 558 (2) on pages 222-223, DOI: 10.11646/phytotaxa.558.2.5, http://zenodo.org/record/700298
- …
