1,409 research outputs found
Synura korshikovii Kapustin & Gusev
No full text<i>Synura korshikovii</i> Kapustin & Gusev (Fig. 4E) <p>DISTRIBUTION. — In the present study this species has been recorded for the second time since its description (Kapustin & Gusev 2015); this species restricted to Polissia so far.</p> REMARKS <p>This recently-described species has scales which are covered with a hexagonal reticulum and spine with a flat apex terminating in a few rows of papillae-like teeth.</p>Published as part of <i>Kapustin, Dmitry A., Gusev, Evgeniy S., Lilitskaya, Galina G. & Kulikovskiy, Maxim S., 2020, Silica-scaled chrysophytes from the Ukrainian Polissia, pp. 121-135 in Cryptogamie, Algologie 20 (12)</i> on page 132, DOI: 10.5252/cryptogamie-algologie2020v41a12, <a href="http://zenodo.org/record/7819057">http://zenodo.org/record/7819057</a>
Mallomonas spinosa Gusev 2012, sp. nov.
No full text<i>Mallomonas spinosa</i> Gusev, <i>sp. nov.</i> (Figs 2–11) <p>Cells ellipsoidal, approximately 20 × 11 µm, covered by scales with spines (Fig. 2). Apical scales lack spines (Fig. 4). Body scales oval, 4.5–5.6 × 2.7–3.6 µm. Shield with densely and regularly spaced papillae (Figs. 6–11). V-rib conspicuous, acute to slightly rounded. Distal ends of arms of V-rib curve and become continuous with anterior submarginal ribs. Anterior submarginal rib forms a prominent asymmetrically placed stout spine with four edges (Fig. 7). Anterior flange with a row of papillae (Fig. 8). Posterior flange smooth with depression containing pores on the base plate (Figs. 5–11). Posterior rim wide and smooth in SEM view. Bristles unknown. Cysts not observed.</p> <p> <b>Type:</b> — VIETNAM. Dong Nai Province: unnamed temporary forest pool in Cat Tien National Park, 11°24’26” N, 107°24’48” E, 23 November 2010, <i>E.S. Gusev s.n.</i> SEM stub CT40/2010 (holotype IBIW!, see Fig. 2), sample CT40 23.11.2010, in collection E.S. Gusev.</p> <p> <b>Distribution and habitat:—</b> This species was found in the type locality and two other water bodies in Khanh Hoa province in Vietnam.</p> <p> <b>Etymology:—</b> The epithet “spinosa” refers to the whole cell being covered by scales with stout spines.</p>Published as part of <i>Gusev, Evgeniy S., 2012, A new species of the genus Mallomonas (Synurophyceae), Mallomonas spinosa sp. nov., from Vietnam, pp. 1-5 in Phytotaxa 66 (1)</i> on pages 2-3, DOI: 10.11646/phytotaxa.66.1.1, <a href="http://zenodo.org/record/5065820">http://zenodo.org/record/5065820</a>
Mallomonas acidophila Gusev & Shkurina & Huan 2023
No full text<i>Mallomonas acidophila</i> Gusev & Shkurina (Figures 2–22) <p>Cell dimensions unknown. Scales are tripartite, oval, 4.3–5.6 × 2.4–3.5 μm, with a dome, a V-rib, anterior submarginal ribs, a shield, anterior and posterior flanges, and a posterior rim. The base plate is devoid of pores. The dome is recessed from the distal margin, shallow, elongated or narrowly elliptical, sometimes curved. The dome can be placed perpendicular to the longitudinal axis of the scale or at an angle to this axis. It is covered with papillae. The shield is ornamented with numerous unevenly distributed papillae. The V-rib is rounded, with a broad and U-shaped base, slightly hooded, with arms that are continuous with the anterior submarginal ribs. The anterior submarginal ribs are of equal length if the dome is perpendicular to the longitudinal axis or unequal if the dome is located at an angle to the longitudinal axis. The anterior flanges are narrow. The posterior rim is narrow and encircles one-third to one-half of the scale perimeter. The posterior flange is wide and smooth. It lacks a secondary siliceous layer in a narrow area along the posterior rim and is strongly thickened in the area adjacent to the V-rib. Bristles are 2.4–7.2 μm long, straight, with a hook-shaped flattened foot, turned at an angle of approximately 45 degrees or less relative to the shaft, gutter-shaped bristle shaft, and a flattened and bifurcated apical tip with a wide, rounded middle part. Cysts are unknown.</p> <p> <b>Holotype (</b> designated here <b>)</b>:— Portion of a single gathering of cells on SEM stub number TTH55 deposited at the Herbarium of the Papanin Institute for Biology of Inland Waters RAS, Borok (IBIW). Material from unnamed reservoir in Thua Thien Hue Province, Vietnam. Sample collected 28 October 2022 by E. Gusev. Figure 3 is a representative scale from the type specimen.</p> <p>Type locality:— Vietnam: unnamed swamp water body in Thua Thien Hue Province, Phong Điễn District, Latitude / Longitude: N16°39.777’ E107°21.905’.</p> <p> <b>Etymology</b>:—The epithet “acidophila” refers to the fact that this species is found at low pH values.</p> <p> <b>Distribution:</b> —To date, <i>M</i>. <i>acidophila</i> has been observed in two neighbouring localities in Vietnam. In addition to the type locality, it has been found in another unnamed water body (Latitude/Longitude: N16°39.694’ E107°21.746’).</p> <p> <b>Observations:</b> — <i>Mallomonas acidophila</i> was found in acidic conditions (pH 5.0–5.2), with low specific conductance values ranged from 17 to 18 μS cm-1, temperature 26 ºC, total phosphorus concentrations 68–133 μL-1, Kjeldahl nitrogen concentrations 406–508 μL-1.</p>Published as part of <i>Gusev, Evgeniy, Shkurina, Nataliya & Huan, Phan Trong, 2023, Mallomonas acidophila sp. nov. (Synurales, Chrysophyceae) - a new species from the tropics with morphological features of fossil taxa, pp. 157-166 in Phytotaxa 620 (2)</i> on page 159, DOI: 10.11646/phytotaxa.620.2.3, <a href="http://zenodo.org/record/10022374">http://zenodo.org/record/10022374</a>
3D structure of the Gusev Crater region
No full texta b s t r a c t a r t i c l e i n f o Article history: Accepted 7 January 2010 Available online 29 January 2010 Keywords: Mars Gusev Crater structural geology stratigraphy Columbia Hills crater count ages Gusev Crater lies within the Aeolis Quadrangle of Mars at the boundary between the northern lowlands and southern highlands. The ancient valley Ma'adim Vallis dissects the highlands south of Gusev Crater and is thought to have fed the crater with sediments. High Resolution Stereo Camera data and Digital Elevation Models were used to construct a geologicgeomorphic map (173.5-178.5°E, 10-18°S) and cross-sections, complemented by data from Mars Orbiter Camera, Mars Orbiter Laser Altimeter and Thermal Emission Imaging System. Three geologic domains are recognised: the highlands in the south, Gusev Crater and lowlands in the north. Twelve units are mapped, with thicknesses ranging from hundred meters to several kilometres. Thicknesses of units, and their bedding attitude, are estimated combining the geologic map and topographic information. Relative ages are determined from crater counts, ranging from Early Noachian for highland units to Middle Amazonian for units in Gusev Crater and in lowlands. Episodes of intense geologic activity (deposition, volcanism, deformation) occur at around 4.0 Ga, 3.7 Ga, and 3.5 Ga. Comparing the geometry of the Gusev Crater with similar sized, filled and un-filled, Martian craters, suggests that the Columbia Hills are relics of the original central peak of Gusev Crater
Mallomonas pseudocorymbosa Gusev, Martynenko & Shkurina 2023, sp. nov.
No full text<i>Mallomonas pseudocorymbosa</i> Gusev, Martynenko & Shkurina <i>sp. nov.</i> (Figure 2). <p> <b>Diagnosis:</b> Scales are oval, tripartite, 4.8–5.9 × 3.3–4.3 µm in size, with or without a dome. The dome is large, rounded, oval or asymmetrical. The V-rib is acute, slightly hooded and its arms continuous with the anterior submarginal ribs. Anterior submarginal ribs are well developed. The anterior flange is wide, especially on the domeless scales, with a row of base plate pores at each side. The posterior flange is wide, with numerous base plate pores distributed on the surface. The shield and posterior flange have a secondary siliceous layer forming circular or elongated oval meshes unevenly distributed on the surface often with areas without development of the secondary layer. Numerous pores are placed on the basal plate. The posterior upturned rim is narrow, with inner struts visible only on TEM images, encircles less than a half of the scale perimeter. Bristles are 13–25 μm long, curved and serrated at the distal half. Shorter bristles have a bifurcated tip with a long terminal spine, and longer bristles have a prolonged thread-like terminal part. Cysts unknown.</p> <p> <i>Holotype (here designated):</i> Portion of a single gathering of cells on SEM stub No. CD8 deposited at the Herbarium, Papanin Institute for Biology of Inland Waters RAS, Borok (IBIW). Material from Ahn Hai Lake, Côn SƠn Island, Bà Rịa-Vũng Tàu Province, Vietnam. Figure 2C illustrates a representative scale from the holotype specimen.</p> <p> <i>Type Locality:</i> Ahn Hai Lake, Côn SƠn Island, Bà Rịa-Vũng Tàu Province, Vietnam. Latitude / Longitude: 8° 40.645’ N 106° 35.867’ E. At the time of collection, the pH was 6.5, temperature 30 °C, and specific conductance 201 µS cm-1. Material was collected by E.S. Gusev and Nguyen-Ngoc Lam on 3 May 2015.</p> <p> <i>Etymology:</i> The species name is derived from the fact that its scales resemble, and could be confused with, those of <i>Mallomonas corymbosa</i>.</p> <p> <i>Distribution:</i> This species has been observed in 17 localities in 13 provinces of Vietnam (Table 1). Scales of this species were also observed in Bangladesh (Takahashi & Hayakawa 1979), China (Wei &Yuan 2001, 2013; Wei <i>et al</i>. 2014), Brazil (Franceschini & Couté 1991)and South Africa (Janse van Vuuren <i>et al</i>. 2022). <i>Mallomonas pseudocorymbosa</i> was found at wide ranges of environmental parameters: pH from 6.1 to 8.6, specific conductance from 62 to 2370 µS cm-1, chlorophyll <i>a</i> values from 5 to 76 µg l –1, and temperature 17–39 ºC (Table 1).</p>Published as part of <i>Gusev, Evgeniy, Martynenko, Nikita, Shkurina, Nataliya & Dien, Tran Duc, 2023, Description of a new species of the genus Mallomonas from section Mallomonas (Synurales, Chrysophyceae) in the tropics, pp. 59-68 in Phytotaxa 618 (1)</i> on page 62, DOI: 10.11646/phytotaxa.618.1.5, <a href="http://zenodo.org/record/8389917">http://zenodo.org/record/8389917</a>
Mallomonas lusca Gusev & Kezlya 2021, sp. nov.
No full text<p> <i>Mallomonas lusca</i> Gusev & Kezlya <i>sp. nov.</i> (Figs. 2–10)</p> <p>Cells are armored with apical domed collar scales, domeless body scales, and small rear scales with short spines. The body scales are rhomboidal and slightly asymmetrical, 2.4–3.2 × 1.7–2.6 μm. Shield is patterned with a reticulated meshwork, creating a dense system of irregular, polygonal apertures, and scattered, delicate papillae. The anterior submarginal rib is well developed, raised above the shield, wide, with 9–12 struts at each side. There is a papilla at the distal side of each strut, adjacent to the anterior flange. A small pore is present in most scales near the distal end of the body scales in the apical flange region. The anterior flange is narrow. The posterior submarginal rib is smooth and fused with the arms of the anterior submarginal rib. There are inner struts, joining the posterior submarginal rib and the shield, only visible on TEM images. There is a conspicuous, rounded pit with a raised, thickened, central area (“island”), which is developed in association with the posterior pore in the angle of the posterior submarginal rib. This rounded pit is surrounded by delicate papillae across the border on the shield. Few papillae are present at the thickened, central area (“island”). The posterior border is smooth and encircles half of the scale. The posterior flange is narrow and smooth. The collar scales are 2.6–3.3 × 1.8–2.1 μm, asymmetrical, elongate and have a broadly rounded, proximal end and narrower distal end, with a well-developed dome. The shield of the collar scales has a similar meshwork pattern to the body scales and an irregular, smooth area near the dome. The dome is oval in outline, with reticulation covering half of the surface, and with a sharply pointed peak at the apex. There are 2–5 rimmed base plate pores in the angle of the posterior submarginal rib. The rear scales are similar in structure to the body scales, but more asymmetrical, bearing small spines and smaller in size, 1.4–2.2 × 1.2–1.6 μm. Bristles are 4–5 μm in length, curved, smooth and pointed. Cysts were not observed.</p> <p> <b>Holotype</b>:—Portion of a single gathering of cells on SEM stub number BT_Prud9 (holotype designated here, Figure 2) deposited at the Herbarium of the Papanin Institute for Biology of Inland Waters RAS, Borok (IBIW). Material from swamp in Binh Thuan Province, Vietnam. Sample collected 26 April 2014 by E.S. Gusev. Figure 2 is a representative scale from the type specimen.</p> <p>Type locality:— Vietnam: swamp pool in Binh Thuan Province near Bau Trang Lake, Latitude / Longitude: N11°03.846’ E108°25.836’.</p> <p> <b>Etymology</b>:—The epithet “lusca” (single-eyed, monocular) refers to the presence of a rounded pit with a raised thickened central area, resembling an eye.</p> <p> <b>Distribution:</b> —To date, <i>Mallomonas lusca</i> has been observed in six localities in Vietnam. In addition to the type locality, it has been found in two other waterbodies in Binh Thuan Province and in Khanh Hoa and Dong Nai Provinces (Table 1). Scales of this species were also reported from one locality in Malaysia (Dürrschmidt & Croome 1985).</p> <p> <b>Observations:</b> — <i>Mallomonas lusca</i> was found in meso- and eutrophic water bodies within a pH range of 6.0–6.7, specific conductance of 23 to 311 μS cm-1, and temperature 29–34 ºC (Table 1).</p>Published as part of <i>Gusev, Evgeniy & Kezlya, Elena, 2021, Mallomonas lusca sp. nov. (Synurales, Chrysophyceae) - a rare species from Southeast Asia, pp. 105-112 in Phytotaxa 529 (1)</i> on pages 107-109, DOI: 10.11646/phytotaxa.529.1.8, <a href="http://zenodo.org/record/5814344">http://zenodo.org/record/5814344</a>
Mallomonas loricata Gusev, Shkurina & Kulikovskiy 2021, sp. nov.
No full text<i>Mallomonas loricata</i> Gusev, Shkurina & Kulikovskiy <i>sp. nov.</i> <p>(figs 2–13)</p> <p>Scales are obovate, 5.7–6.8 × 3.8–4.4 μm in size. A wide posterior rim encircles one-half to two-thirds of the scale perimeter (figs 2–4). Evenly spaced small base-plate pores cover the scale surface and are often more widely spaced across the distal part (figs 5–6). One large, rimmed pore is situated in the posterior region and is surrounded by a cluster of minute pores. A thick secondary siliceous layer with internal reticulation covers almost the entire surface of the scales, excluding a small, rounded area surrounding the large, rimmed pore (figs 2–4 and 8–10). Bristles are 12–14 μm long, smooth, slightly curved, and possess a serrated distal tip; the bristle shaft is tubular, with a longitudinal slit (figs 7, 12–13). Cysts unknown.</p> <p> <b>Holotype</b>:—Portion of a single gathering of cells on SEM stub no. BD25 (holotype designated here in fig. 2) deposited at the Herbarium, Papanin Institute for Biology of Inland Waters RAS, Borok (IBIW). Material from My Binh Reservoir, Binh Dinh Province, VIETNAM, collected by E.S. Gusev on the 23 d of May, 2018. Figure 2 illustrates a representative scale from the specimen.</p> <p> <b>Type locality:</b> — VIETNAM: Binh Dinh Province, My Binh Reservoir, Latitude / Longitude: 14°33.869’ N, 108°59.427’ E.</p> <p> <b>Epithet</b>:—The epithet refers to the thick scales, forming armor, surrounding the cell.</p> <p> <b>Distribution</b>:—In addition to the type locality, this species has been observed from the other regions of Vietnam: Binh Dinh, Binh Thuan, Dak Lak, Khanh Hoa, Phu Yen, Quang Tri, and Thua Thien Hue provinces, and in Hanoi (Table 1). Also, scales of this species were reported from Singapore and Malaysia under the name <i>M. matvienkoae</i> (Neustupa & Řezáčová 2007: 225, fig 7). <i>Mallomonas loricata</i> was found in a wide range of environmental parameters including pH (6.1–8.3), specific conductance (32–287 µS cm-1) and temperature (28–36 ºC) (Table 1).</p>Published as part of <i>Gusev, Evgeniy, Shkurina, Nataliya & Kulikovskiy, Maxim, 2021, Mallomonas loricata sp. nov. (Synurales, Chrysophyceae), a new tropical species from section Planae, pp. 225-233 in Phytotaxa 500 (3)</i> on page 229, DOI: 10.11646/phytotaxa.500.3.6, <a href="http://zenodo.org/record/5424594">http://zenodo.org/record/5424594</a>
Mallomonas voloshkoae Gusev & Němcová & Kulikovskiy 2022, sp. nov.
No full text<i>Mallomonas voloshkoae sp. nov.</i> Gusev, Němcová & Kulikovskiy (Figs. 2–18) <p> <b>Description</b>: Scales are 3.4–4.5 × 1.7–2.4 μm (up to 2.6 μm with winged flanges), oval to obovate with lateral incurvings. Scales possess a posterior rim, a V-rib, anterior ribs and flanges, and a dome. The dome is subcircular and smooth. The shield is marked with four to six regularly spaced transverse ribs. A group of numerous pores, usually more than 20, is located at the angle of the V-rib in the posterior part of the shield. Anterior flanges are wide, in the form of wing-like extensions, with three to seven closely spaced struts. Anterior flanges surround the dome. The anterior submarginal ribs are well developed. The V-rib on the scales is acutely angled, slightly hooded, and continues on wing-like extensions. The posterior rim bears internal struts but is smooth on the surface. The posterior flange bears approximately 14–18 struts and scattered base-plate pores, sometimes organised to form a row (Fig. 6). Bristles are 4.5–6.2 μm in length, slightly curved. The distal end of the bristle is widened. The tip is bifurcated with unequal diverging branches. One branch is short and sharp, whereas the other is wide with an acute tip and flat dorsal side (Figs. 10–14). Cysts were not observed.</p> <p> <b>Holotype specimen</b>: Portion of a single gathering of cells on SEM stub No. B137 deposited at the Herbarium, Papanin Institute for Biology of Inland Waters RAS, Borok (IBIW). Material from an unnamed lake in the Barguzin Mountains, Republic of Buryatia, Russia, collected by E.S. Gusev and M.S. Kulikovskiy on 18 July 2014. Figure 2 illustrates a representative scale from the holotype specimen. <b>Type Locality</b>: Unnamed lake 1 in Barguzin Mountains, Republic of Buryatia, Russia. Latitude/Longitude: N55° 26.250’ E110° 16.363’.</p> <p> <b>Epithet</b>: The species is named in honour of Lyudmila Voloshko, a well-known specialist in chrysophyte algae.</p> <p> <b>Distribution</b>: In addition to the type locality, this species was observed in other lakes of the Transbaikal area (Table 1). <i>Mallomonas voloshkoae</i> was found in acidic to slightly acidic conditions (pH from 5.2 to 6.5) with a specific conductance ranging from 2 to 14 µS cm-1 and a temperature of 12–20°C (Table 1).</p>Published as part of <i>Gusev, Evgeniy, Němcová, Yvonne & Kulikovskiy, Maxim, 2022, Mallomonas voloshkoae sp. nov. (Synurales, Chrysophyceae) and distribution of M. pechlaneri in mountain lakes of Siberia, pp. 221-229 in Phytotaxa 530 (2)</i> on pages 224-226, DOI: 10.11646/phytotaxa.530.2.9, <a href="http://zenodo.org/record/5832781">http://zenodo.org/record/5832781</a>
Mallomonas pseudomatvienkoae B. Y. Jo, W. Shin, H. S. Kim, Siver & R. A. Andersen
No full text<i>Mallomonas</i> cf. <i>pseudomatvienkoae</i> B.Y.Jo, W.Shin, H.S.Kim, Siver & R.A.Andersen (Fig. 3C) <p> DISTRIBUTION. — South Korea (Jo <i>et al.</i> 2013); Russia (Gusev <i>et al.</i> 2019b); probably a widely distributed taxon but often erroneously identified as <i>M. matvienkoae</i>.</p> REMARKS <p>The scales of this species have base-plate pores restricted to the distal part and a thick secondary layer that covers the distal one-half to two-thirds of the scale. A single scale observed by us was entirely covered by the secondary layer of silica.</p>Published as part of <i>Kapustin, Dmitry A., Gusev, Evgeniy S., Lilitskaya, Galina G. & Kulikovskiy, Maxim S., 2020, Silica-scaled chrysophytes from the Ukrainian Polissia, pp. 121-135 in Cryptogamie, Algologie 20 (12)</i> on page 130, DOI: 10.5252/cryptogamie-algologie2020v41a12, <a href="http://zenodo.org/record/7819057">http://zenodo.org/record/7819057</a>
Mallomonas corcontica L. S. Peterfi & Momeu
No full text<i>Mallomonas corcontica</i> (Kalina) L.Ş.Péterfi & Momeu (Fig. 2I) <p>DISTRIBUTION. — Restricted to northern temperate regions (Kristiansen & Preisig 2007; Řezáčová & Neustupa 2007).</p> REMARKS <p>The scales of this species are characterized by the struts radiating from the proximal border of the dome (Kristiansen & Preisig 2007).</p>Published as part of <i>Kapustin, Dmitry A., Gusev, Evgeniy S., Lilitskaya, Galina G. & Kulikovskiy, Maxim S., 2020, Silica-scaled chrysophytes from the Ukrainian Polissia, pp. 121-135 in Cryptogamie, Algologie 20 (12)</i> on page 128, DOI: 10.5252/cryptogamie-algologie2020v41a12, <a href="http://zenodo.org/record/7819057">http://zenodo.org/record/7819057</a>
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