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Gonyostomum
''Gonyostomum'' is a genus of freshwater algae in the class Raphidophyceae. They include the species '' Gonyostomum semen'', which causes nuisance algal blooms. References {{Taxonbar, from=Q5582133 Ochrophyta Heterokont genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonyostomum Semen
Gonyostomum semen is a species of freshwater algae in the genus '' Gonyostomum'', with worldwide distribution. They cause nuisance algal blooms and are known to cause allergic reactions to people swimming in lakes. Distribution This freshwater microalgal species is globally distributed. It usually occurs in small, acidic lakes with high concentrations of dissolved organic carbon Dissolved organic carbon (DOC) is the fraction of organic carbon operationally defined as that which can pass through a filter with a pore size typically between 0.22 and 0.7 micrometers. The fraction remaining on the filter is called particu ..., which result in sharp gradients of light intensity due to rapid attenuation of light with depth. During the last decades, ''G. semen'' has spread in northern Europe to many non-humic lakes with higher pH. There is evidence that brownification of lakes in these areas, decreasing pH and higher water temperature initiated the spreading of this species. P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raphidophyceae
The raphidophytes, formally known as Raphidomonadea or Raphidophyceae (formerly referred to as Chloromonadophyceae and Chloromonadineae), are a small group of eukaryotic algae that includes both marine and freshwater species. All raphidophytes are unicellular, with large cells (50 to 100 μm), but no cell walls. Raphidophytes possess a pair of flagella, organised such that both originate from the same invagination (or gullet). One flagellum points forwards, and is covered in hair-like mastigonemes, while the other points backwards across the cell surface, lying within a ventral groove. Raphidophytes contain numerous ellipsoid chloroplasts, which contain chlorophylls a, c1 and c2. They also make use of accessory pigments including β-carotene and diadinoxanthin. Unlike other heterokontophytes, raphidophytes do not possess the photoreceptive organelle (or eyespot) typical of this group. In terms of ecology, raphidophytes occur as photosynthetic autotrophs across a range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterokont
Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line of eukaryotes. Most are algae, ranging from the giant multicellular kelp to the unicellular diatoms, which are a primary component of plankton. Other notable members of the Stramenopiles include the (generally) parasitic oomycetes, including ''Phytophthora'', which caused the Great Famine of Ireland, and ''Pythium'', which causes seed rot and damping off. The name "heterokont" refers to the type of motile life cycle stage, in which the flagellated cells possess two differently arranged flagella (see zoospore). History In 1899, Alexander Luther created the term "Heterokontae" for some algae with unequal flagella, today called Xanthophyceae. Later, some authors (e.g., Copeland, 1956) included other groups in Heterokonta, expanding the name's sense. The term continues to be applied in different ways, leading to Heterokontophyta being applie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAR Supergroup
The SAR supergroup, also just SAR or Harosa, is a clade that includes stramenopiles (heterokonts), alveolates, and Rhizaria. The name is an acronym derived from the first letters of each of these clades; it has been alternatively spelled "RAS". The term "Harosa" (at the subkingdom level) has also been used. The SAR supergroup is a node-based taxon. Note that as a formal taxon, "Sar" has only its first letter capitalized, while the earlier abbreviation, SAR, retains all uppercase letters. Both names refer to the same group of organisms, unless further taxonomic revisions deem otherwise. Members of the SAR supergroup were once included under the separate supergroups Chromalveolata (Chromista and Alveolata) and Rhizaria, until phylogenetic studies confirmed that stramenopiles and alveolates diverged with Rhizaria. This apparently excluded haptophytes and cryptomonads, leading Okamoto ''et al.'' (2009) to propose the clade Hacrobia to accommodate them. Phylogeny Based on a compi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ochrophyta
The ochrophytes, subphylum Ochrophytina, is a group of mostly photosynthetic heterokonts. Their plastid is of red algal origin. The classification of the group is still being worked out. Originally, the ochrophytes were regarded as a phylum denominated Ochrophyta. Some authors (e.g., Cavalier-Smith) divided it into two subphyla, Phaeista Cavalier-Smith 1995 (comprising Hypogyristea and Chrysista in some classifications, or Limnista and Marista in others) and Khakista Cavalier-Smith, 2000 (comprising '' Bolidomonas'' and diatoms). Others prefer not to use the subphyla, listing only lower taxa (e.g., Reviers, 2002, Guiry & Guiry, 2014). However, it is currently regarded as a subphylum inside of the phylum Gyrista, along with Pseudofungi and Bigyromonada. It contains two infraphyla: Diatomista, containing diatoms and related groups, and Chrysista, containing brown and golden algae and related groups. Phylogeny The cladogram below shows the evolutionary relationships between a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algal Blooms
An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ''algae'' encompasses many types of aquatic photosynthetic organisms, both macroscopic multicellular organisms like seaweed and microscopic unicellular organisms like cyanobacteria. ''Algal bloom'' commonly refers to the rapid growth of microscopic unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest. Algal blooms are the result of a nutrient, like nitrogen or phosphorus from various sources (for example fertilizer runoff or other forms of nutrient pollution), entering the aquatic system and causing excessive growth of algae. An algal bloom affects the whole ecosystem. Consequences range from the benign feeding of higher trophic levels to more harmful effects like blocking sunlight from reaching other or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
