| Helicosporidium | |
|---|---|
 | |
| Helicosporidium under a light microscope | |
Scientific classification  | |
| (unranked): | Viridiplantae |
| Division: | Chlorophyta |
| Class: | Trebouxiophyceae |
| Order: | Chlorellales |
| Family: | Chlorellaceae |
| Genus: | Helicosporidium Keilin, 1921 [1] |
| Species | |
Helicosporidium is a genus of colorless, pathogenic algae in the class Trebouxiophyceae of the green algae. [2] [3] It is a parasite found in the gut of insects, and a close relative of Prototheca . [4]
Algae is an informal term for a large and diverse group of photosynthetic, eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as Chlorella, Prototheca and the diatoms, to multicellular forms, such as the giant kelp, a large brown algae which may grow up to 50 metres (160 ft) in length. Most are aquatic and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, Spirogyra and stoneworts.
Chlamydomonadales, also known as Volvocales, are an order of flagellated or pseudociliated green algae, specifically of the Chlorophyceae. Chlamydomonadales can form planar or spherical colonies. These vary from Gonium up to Volvox. Each cell has two flagella, and is similar in appearance to Chlamydomonas, with the flagella throughout the colony moving in coordination.
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.
In biology, a biological life cycle is a series of changes in form that an organism undergoes, returning to the starting state. "The concept is closely related to those of the life history, development and ontogeny, but differs from them in stressing renewal." Transitions of form may involve growth, asexual reproduction, or sexual reproduction.
A coenocyte is a multinucleate cell which can result from multiple nuclear divisions without their accompanying cytokinesis, in contrast to a syncytium, which results from cellular aggregation followed by dissolution of the cell membranes inside the mass. The word syncytium in animal embryology is used to refer to the coenocytic blastoderm of invertebrates. A coenocytic colony is referred to as a coenobium, and most coenobia are composed of a distinct number of cells, often as a multiple of two.
Protothecosis, otherwise known as Algaemia, is a disease found in dogs, cats, cattle, and humans caused by a type of green alga known as Prototheca that lacks chlorophyll and enters the human or animal bloodstream. It and its close relative Helicosporidium are unusual in that they are actually green algae that have become parasites. The two most common species are Prototheca wickerhamii and Prototheca zopfii. Both are known to cause disease in dogs, while most human cases are caused by P. wickerhami. Prototheca is found worldwide in sewage and soil. Infection is rare despite high exposure, and can be related to a defective immune system. In dogs, females and Collies are most commonly affected.
Prasiolales is an order of green algae in the class Trebouxiophyceae.
Ulotrichales is an order of green algae in the class Ulvophyceae.
Chlorellaceae are a family of green algae in the order Chlorellales.
Kirchneriella is a genus of green algae in the family Selenastraceae. It is found in freshwater habitats, as phytoplankton or metaphyton.
Oltmannsiellopsis is a genus of marine colonial flagellate green algae in the Oltmannsiellopsidaceae family of Chlorophyta. It was named in reference to the similar genus Oltmannsiella. It has three species, O. viridis, which forms four-celled colonies, O. unicellularis, which is single celled, and O. geminata, which forms two-celled colonies. In Japanese it is called ウミイカダモ.
Quadrigula is a genus of green algae in the family Selenastraceae. It is commonly found in freshwater habitats as phytoplankton.
Trentepohlia is a genus of filamentous chlorophyte green algae in the family Trentepohliaceae, living free on terrestrial supports such as tree trunks and wet rocks or symbiotically in lichens. The filaments of Trentepohlia have a strong orange colour caused by the presence of large quantities of carotenoid pigments which mask the green of the chlorophyll.
The Desmidiaceae are one of four families of charophyte green algae in the order Desmidiales (desmids).
Cosmarium is a genus of freshwater organisms belonging to the Charophyta, a division of green algae from which the land plants (Embryophyta) emerged.
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.
Fluorenol, also known as hydrafinil, is an alcohol derivative of fluorene. In the most significant isomer, fluoren-9-ol or 9-hydroxyfluorene, the hydroxy group is located on the bridging carbon between the two benzene rings. Hydroxyfluorene can be converted to fluorenone by oxidation. It is a white-cream colored solid at room temperature.
Chromerida is a phylum of unicellular alveolates, which includes photosynthetic species Chromera velia and Vitrella brassicaformis. General features of the phylum include spherical cells each with a thick cell wall, chloroplast present with chlorophyll a only, and an internal developing flagellum at some lifestages.
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