Synurid

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Synurids
Synura.jpg
A colony of Synura sp.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Clade: Diaphoretickes
Clade: SAR
Clade: Stramenopiles
Phylum: Gyrista
Subphylum: Ochrophytina
Class: Chrysophyceae
Order: Synurales
Andersen, 1987
Genera [1]

The synurids (order Synurales) are a small group of heterokont algae, found mostly in freshwater environments, characterized by cells covered in silica scales. [2]

Contents

Characteristics

A single cell of the freshwater algae species Synura petersenii, false color image created using SEM Synura petersenii.png
A single cell of the freshwater algae species Synura petersenii, false color image created using SEM

They are covered in silicate scales and spines. In Synura, these are formed on the surface of the chloroplasts, [3] two of which are usually present, but sometimes only one divided into two lobes is seen. The cells have two heterokont flagella, inserted parallel to one another at the anterior, whose ultrastructure is a distinguishing characteristic of the group. Both asexual and isogamous sexual reproduction occur.

Morphology

[[File:2023 Synurophyte.svg|center|thumb|upright=2|

Representation of a Synurophyte
  1. Flagellum with mastigonemes
  2. Residual flagellum with swelling
  3. Surface scale
  4. Golgi apparatus; modifies proteins and sends them out of the cell
  5. Plastid membranes (4, secondary red)
  6. Thylakoid, site of the light-dependent reactions of photosynthesis
  7. Nucleus
  8. Endoplasmic reticulum, the transport network for molecules going to specific parts of the cell
  9. Mitochondrion, creates ATP (energy) for the cell, tubular cristae
  10. Lysosome, holds enzymes
  11. Phagocytic vacuole with prey
  12. Bristle
  13. Dome
  14. V-rib
  15. Shield
  16. Hood
  17. Flange
  18. ]]

Classification

Synurales are divided into three families, each with one genus: [4]

History

The genus Synura was proposed in 1834 by the German microscopist Christian Gottfried Ehrenberg (1795–1876). [5]

The synurids were originally included among the golden algae in the order Ochromonadales as the family Mallomonadaceae or as the family Synuraceae . They were formally defined as a separate group by Andersen in 1987, who placed them in their own class Synurophyceae, based on an earlier approach of more narrowly defining major lineages of chrysophyte algae by British phycologist David Hibberd. [6] [7]

The Chrysophyceae and Synurophyceae are currently recognized as closely related taxa within the Stramenopiles. [8] [9] Present classifications include the synurids as an order (Synurales) within Chrysophyceae. [2] [10]

Related Research Articles

<span class="mw-page-title-main">Stramenopile</span> Clade of eukaryotes

The Stramenopiles, also called Heterokonts, are a clade of organisms distinguished by the presence of stiff tripartite external hairs. In most species, the hairs are attached to flagella, in some they are attached to other areas of the cellular surface, and in some they have been secondarily lost. Stramenopiles represent one of the three major clades in the SAR supergroup, along with Alveolata and Rhizaria.

<span class="mw-page-title-main">Haptophyte</span> Type of algae

The haptophytes, classified either as the Haptophyta, Haptophytina or Prymnesiophyta, are a clade of algae.

<span class="mw-page-title-main">Pedinellales</span> Order of single-celled organisms

Pedinellales (ICN) or Pedinellida (ICZN) is a group of single-celled algae found in both marine environments and freshwater.

<span class="mw-page-title-main">Axodine</span> Class of single-celled organisms

The axodines are a group of unicellular stramenopiles that includes silicoflagellate and rhizochromulinid algae, actinomonad heterotrophic flagellates and actinophryid heliozoa. Alternative classifications treat the dictyochophytes as heterokont algae, or as Chrysophyceae. Other overlapping taxonomic concepts include the Actinochrysophyceae, Actinochrysea or Dictyochophyceae sensu lato. The grouping was proposed on the basis of ultrastructural similarities, and is consistent with subsequent molecular comparisons.

<span class="mw-page-title-main">Chromista</span> Eukaryotic biological kingdom

Chromista is a proposed but polyphyletic biological kingdom, refined from the Chromalveolata, consisting of single-celled and multicellular eukaryotic species that share similar features in their photosynthetic organelles (plastids). It includes all eukaryotes whose plastids contain chlorophyll c and are surrounded by four membranes. If the ancestor already possessed chloroplasts derived by endosymbiosis from red algae, all non-photosynthetic Chromista have secondarily lost the ability to photosynthesise. Its members might have arisen independently as separate evolutionary groups from the last eukaryotic common ancestor.

<span class="mw-page-title-main">Golden algae</span> Class of algae

The Chrysophyceae, usually called chrysophytes, chrysomonads, golden-brown algae or golden algae, are a large group of algae, found mostly in freshwater. Golden algae is also commonly used to refer to a single species, Prymnesium parvum, which causes fish kills.

<span class="mw-page-title-main">Bicosoecida</span> Order of protists

Bicosoecida (ICZN) or Bicosoecales/Bicoecea (ICBN) is an order of Bikosea, a small group of unicellular flagellates, included among the stramenopiles. Informally known as bicosoecids, they are free-living cells, with no chloroplasts, and in some genera are encased in a lorica.

<span class="mw-page-title-main">Ochrophyte</span> Phylum of algae

Ochrophytes, also known as heterokontophytes or stramenochromes, are a group of algae. They are the photosynthetic stramenopiles, a group of eukaryotes, organisms with a cell nucleus, characterized by the presence of two unequal flagella, one of which has tripartite hairs called mastigonemes. In particular, they are characterized by photosynthetic organelles or plastids enclosed by four membranes, with membrane-bound compartments called thylakoids organized in piles of three, chlorophyll a and c as their photosynthetic pigments, and additional pigments such as β-carotene and xanthophylls. Ochrophytes are one of the most diverse lineages of eukaryotes, containing ecologically important algae such as brown algae and diatoms. They are classified either as phylum Ochrophyta or Heterokontophyta, or as subphylum Ochrophytina within phylum Gyrista. Their plastids are of red algal origin.

Phaeothamniophycidae is a subclass of heterokont algae. It contains two orders, Phaeothamniales and Pleurochloridellales, and consists of species separated from Chrysophyceae.

<span class="mw-page-title-main">Bigyra</span> Phylum of single-celled organisms

Bigyra is a phylum of microscopic eukaryotes that are found at the base of the Stramenopiles clade. It includes three well-known heterotrophic groups Bicosoecida, Opalinata and Labyrinthulomycetes, as well as several small clades initially discovered through environmental DNA samples: Nanomonadea, Placididea, Opalomonadea and Eogyrea. The classification of Bigyra has changed several times since its origin, and its monophyly remains unresolved.

Mallomonas lacuna is a species of heterokont algae. It is a tiny free-living cell, about the width of a human hair. It has ornate scales and bristles, as well as long spines. It is a relatively common part of lake or pond plankton. It differs from its cogenerates by the number, distribution, and size of its base plate pores, the secondary structures on the scale surfaces, together with characteristics of its bristles.

Mallomonas hexareticulata is a species of heterokont algae. It is a tiny free-living cell, about the width of a human hair. It has ornate scales and bristles, as well as long spines. It is a relatively common part of lake or pond plankton. It differs from its cogenerates by the number, distribution, and size of its base plate pores, the secondary structures on the scale surfaces, together with characteristics of its bristles.

Mallomonas pseudomatvienkoae is a species of heterokont algae. It is a tiny free-living cell, about the width of a human hair. It has ornate scales and bristles, as well as long spines. It is a relatively common part of lake or pond plankton. It differs from its cogenerates by the number, distribution, and size of its base plate pores, the secondary structures on the scale surfaces, together with characteristics of its bristles.

Mallomonas sorohexareticulata is a species of heterokont algae. It is a tiny free-living cell, about the width of a human hair. It has ornate scales and bristles, as well as long spines. It is a relatively common part of lake or pond plankton. It differs from its cogenerates by the number, distribution, and size of its base plate pores, the secondary structures on the scale surfaces, together with characteristics of its bristles.

Mallomonas pleuriforamen is an extinct species of heterokont algae. It was first found in Middle Eocene lacustrine deposits from northwestern Canada. It was a tiny free-living cell, about the width of a human hair. It had ornate scales and bristles, as well as long spines. It was a relatively common part of lake or pond plankton. It differs from its cogenerates by the number, distribution, and size of its base plate pores, the secondary structures on the scale surfaces, together with characteristics of its bristles.

<i>Mallomonas</i> Genus of single-celled organisms

Mallomonas is a genus comprising unicellular algal eukaryotes and characterized by their intricate cell coverings made of silica scales and bristles. The group was first named and classified by Dr. Maximilian Perty in 1852. These organisms live in freshwater and are widely distributed around the world. Some well known species include Mallomonas caudata and Mallomonas splendens.

<i>Synura</i> Genus of heterokont algae

Synura is a genus of colonial chrysomonad algae covered with silica scales. It is the most conspicuous genus of the order Synurales.

<span class="mw-page-title-main">Ultrastructural identity</span>

Ultrastructural identity is a concept in biology. It asserts that evolutionary lineages of eukaryotes in general and protists in particular can be distinguished by complements and arrangements of cellular organelles. These ultrastructural components can be visualized by electron microscopy.

<span class="mw-page-title-main">Gyrista</span> Phylum of eukaryotic organisms

Gyrista is a phylum of heterokont protists containing three diverse groups: the mostly photosynthetic Ochrophyta, the parasitic Pseudofungi, and the recently described group of nanoflagellates known as Bigyromonada. Members of this phylum are characterized by the presence of a helix or a double helix/ring system in the ciliary transition region.

<span class="mw-page-title-main">Ochromonadales</span> Order of algae

Ochromonadales is an order of single-celled algae belonging to the class Chrysophyceae, also known as golden algae. Initially it contained numerous groups of flagellates that were not closely related. During the late 20th century, advancements in molecular and ultrastructural studies allowed the transfer of many of these groups out of Ochromonadales, and the order was reduced to a single family Ochromonadaceae. They are aquatic single-celled flagellated algae, with two heterokont flagella each, some of which have secondarily lost their chloroplasts and appear colorless.

References

  1. Škaloud, Pavel; Kristiansen, Jørgen; Škaloudová, Magda (July 2013). "Developments in the taxonomy of silica-scaled chrysophytes – from morphological and ultrastructural to molecular approaches". Nordic Journal of Botany. 31 (4) (published August 2013): 385–402. doi:10.1111/j.1756-1051.2013.00119.x.
  2. 1 2 Škaloud P, Škaloudová M, Procházková A, Němcová Y (2014). "Morphological delineation and distribution patterns of four newly described species within the Synura petersenii species complex (Chrysophyceae, Stramenopiles)". European Journal of Phycology. 49 (2): 213–229. Bibcode:2014EJPhy..49..213S. doi: 10.1080/09670262.2014.905710 .
  3. Barry S.C. Leadbeater (1990), "Ultrastructure and assembly of the scale case in Synura (Synurophyceae Andersen)", British Phycological Journal, 25 (2): 117–132, doi: 10.1080/00071619000650111
  4. Bok Yeon Jo; Jong Im Kim; Pavel Škaloud; Peter A. Siver; Woongghi Shin (1 September 2016). "Multigene phylogeny of Synura (Synurophyceae) and descriptions of four new species based on morphological and DNA evidence". European Journal of Phycology. 51 (4): 413–430. doi:10.1080/09670262.2016.1201700. ISSN   0967-0262. Wikidata   Q99647124.
  5. See:
    • Ehrenberg (1833). "Dritter Beitrag zur Erkenntniss grosser Organisation in der Richtung des kleinsten Raumes" [Third contribution to [our] knowledge of greater organization in the direction of the smallest realm]. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin [Treatises of the Royal Academy of Sciences in Berlin] (in German). 1833: 145–336. From p. 281: Ehrenberg created a new family, Volvocina, " ... wozu ich die vier neuen Gattungen Chlamidomonas, Syncrypta, Synura, und Uroglena stelle." ( ... into which I place the four new genera Chlamidomonas, Syncrypta, Synura, and Uroglena.) [Note: According to p. 145, Ehrenberg's paper was first presented in 1832, revised somewhat, and published in 1834.]
    • See also: AlgaeBase: Synura Ehrenberg, 1834
  6. Hibberd, D. J. (1976). "The ultrastructure and taxonomy of the Chrysophyceae and Prymnesiophyceae (Haptophyceae): A survey with some new observations on the ultrastructure of the Chrysophyceae". Botanical Journal of the Linnean Society. 72 (2): 55–80. doi:10.1111/j.1095-8339.1976.tb01352.x.
  7. Hibberd, David J. (1979). "The structure and phylogenetic significance of the flagellar transition region in the chlorophyll c-containing algae". Biosystems. 11 (4): 243–261. Bibcode:1979BiSys..11..243H. doi:10.1016/0303-2647(79)90025-X. PMID   396946.
  8. Grant J, Tekle YI, Anderson OR, Patterson DJ, Katz LA (March 2009). "Multigene Evidence for the Placement of a Heterotrophic Amoeboid Lineage Leukarachnion sp. among Photosynthetic Stramenopiles". Protist. 160 (3): 376–85. doi:10.1016/j.protis.2009.01.001. PMID   19282238.
  9. W. Vyverman; G. Cronberg (March 1993). "Scale bearing chrysophytes from Papua New Guinea". Nordic Journal of Botany . 13 (1): 111–20. doi:10.1111/j.1756-1051.1993.tb00022.x.
  10. Cavalier-Smith, Thomas (2017). "Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences". Protoplasma. 255 (1): 297–357. doi:10.1007/s00709-017-1147-3. PMC   5756292 . PMID   28875267.