| Spinoclosterium | |
|---|---|
Scientific classification  | |
| (unranked): | Viridiplantae |
| (unranked): | Charophyta |
| Class: | Zygnematophyceae |
| Order: | Desmidiales |
| Family: | Closteriaceae |
| Genus: | Spinoclosterium C.Bernard |
| Species | |
Spinoclosterium is a genus of green algae, specifically of the Closteriaceae. [1] It is rare, but widely distributed in freshwater regions throughout the world. [2]
Spinoclosterium consists of solitary cells. Cells are relatively large, flattened, and are crescent-shaped in outline. The midregion is somewhat widened. [3] The apices are broadly rounded to subcapitate, and are furnished with a stout, straight spine. Cells consist of two symmetrical halves, called semicells. Each semicell contains a single, axial chloroplast containing several pyrenoids scattered throughout. [4] Each cell apex contains a vacuole. [3]
With its crescent-shaped cells, Spinoclosterium is similar to its sister genus Closterium , but is easily distinguished by the tips of the cells bearing a spine. [3]
Spinoclosterium is able to reproduce asexually and sexually. It is unusual for its mode of asexual cell division, which involves a pale pink granular mucilage. The cell secretes this mucilage in a ring around its midregion, then completes mitosis and divides into two daughter cells. Like other desmids, the two daughter cells are asymmetrical at this stage, with one adult semicell and one newly formed semicell. However, the mucilage holds the two cells roughly in place until cells are fully developed in size. This means that unlike other desmids that finish cell division with daughter cells aligned head-to-head, the daughter cells of Spinoclosterium are aligned side-to-side. [2]
Sexual reproduction is anisogamous, with male and female gametes. Cells reproduce sexually by conjugating. The female cell lies next to the male cell and the two form a tube between them. The protoplast of the male cell shrinks inside and moves through the tube into the female cell, forming a zygote. The zygote matures into a full zygospore after a few days; the zygospore is irregularly ellipsoid in shape. [2]
When the zygospore germinates, it releases its contents and meiosis occurs, of which two of the four meiotic producte survive and the other two are aborted. The post-meiotic cells (called two gones) form an additional cell wall, and finally the each gone divides into two asymmetrical juvenile cells, releasing the cells by gelatinization of the double cell wall. [2]
Desmidiales, commonly called the desmids, are an order in the Charophyta, a division of green algae in which the land plants (Embryophyta) emerged. Desmids consist of single-celled microscopic green algae. Because desmids are highly symmetrical, attractive, and come in a diversity of forms, they are popular subjects for microscopists, both amateur and professional.
Micrasterias is a unicellular green alga of the order Desmidiales. Its species vary in size reaching up to hundreds of microns.
Sporogenesis is the production of spores in biology. The term is also used to refer to the process of reproduction via spores. Reproductive spores were found to be formed in eukaryotic organisms, such as plants, algae and fungi, during their normal reproductive life cycle. Dormant spores are formed, for example by certain fungi and algae, primarily in response to unfavorable growing conditions. Most eukaryotic spores are haploid and form through cell division, though some types are diploid sor dikaryons and form through cell fusion.we can also say this type of reproduction as single pollination
Atractomorpha is a genus in the Sphaeropleaceae, a family of green algae. The genus name is derived from Greek and means "spindle-shaped" or "arrow-shaped", and refers to the shape of the cells.
Chlainomonas is a genus of algae in the family Chlamydomonadaceae. They are found in freshwater habitats or on snow, where they are one of the main algae responsible for causing watermelon snow.
Coelastropsis is a genus of green algae in the family Scenedesmaceae, containing the single species Coelastropsis costata. It is found in freshwater lakes and bogs, usually associated with mosses and filamentous algae. It has been recorded in Europe, Cuba and possibly New Zealand.
Lagerheimia is a genus of green algae in the family Oocystaceae. It is commonly found in freshwater habitats all over the world, although some species are rare and have only been recorded from Europe or the United States.
Raphidocelis is a genus of green algae in the family Selenastraceae. They are found in freshwater habitats.
Sorastrum is a genus of green algae in the family Hydrodictyaceae. It is a component of the phytoplankton of freshwater ponds, lakes, and ditches. Sorastrum is common in tropical to temperate regions of the world, but due to its small size it is often overlooked.
Sphaeroplea is a genus of green algae in the family Sphaeropleaceae. It was first circumscribed by the Swedish botanist Carl Adolph Agardh in 1824.
Treubaria is a genus of green algae, the sole genus in the family Treubariaceae. Treubaria is found in freshwater habitats and has a cosmopolitan distribution.
Closterium is a genus of desmid, a group of charophyte green algae. It is placed in the family Closteriaceae. Species of Closterium are a common component of freshwater microalgae flora worldwide.
Cosmarium is a genus of freshwater organisms belonging to the Charophyta, a division of green algae from which the land plants (Embryophyta) emerged.
Desmidium is a genus of green algae, specifically of the Desmidiaceae.
Pleurotaenium is a genus of green algae, specifically of the desmids (Desmidiaceae).
Staurodesmus is a genus of green algae, specifically of the Desmidiaceae.
Triploceras is a genus of desmid in the family Desmidiaceae.
Xanthidium is a genus of green algae, specifically of the Desmidiaceae.
Zygnematophyceae is a class of green algae in the paraphylum streptophyte algae, also referred to as Charophyta, consisting of more than 4000 described species. The Zygnematophyceae are the sister clade of the Embryophyta.
Prescottiella is a genus of green algae in the family Desmidiaceae, containing the single species Prescottiella sudanensis. Originally classified as Micrasterias sudanensis in 1958, it was moved into its own genus by Carlos E. M. Bicudo in 1976, due to its asymmetric character. It is named after Gerald Webber Prescott, an American phycologist.