The golden algae are algal species that are mostly found in freshwater, according to phycology. They are also known as chrysophytes. They are members of the phylum Chrysophyta, an algal phylum that also includes xanthophytes (yellow-green algae) and diatoms. The golden algae, in particular, are members of the phylum’s subgroup, class Chrysophyceae. They are distinguished primarily by the presence of a high concentration of the pigment fucoxanthin.
As a result, they range in colour from brownish to golden brown. A large number of them have been flagellated. Some of them, like Chromulina sp., only have one flagellum. Others, such as Ochromonas sp., have two flagella. Although most chrysophytes are flagellated, some, such as Chrysaccus sp., are not. There are also amoeboid members of this class, such as Chrysamoeba sp., who go through flagellate stages.
Golden Algae in Brief
Golden algae (which belongs to class Chrysophyceae), also known as golden-brown algae, is a class of approximately 33 genera and 1,200 species of algae (division Chromophyta) found in both marine and fresh waters. The group’s form is fairly diverse, and its taxonomy is debatable. The majority of golden algae are single-celled biflagellates with two distinct flagella.
They are distinguished by the presence of the pigment fucoxanthin and the use of oil droplets as a food reserve. Many are encased in a silica cyst which is known as a statocyst or also known as the statospore, the ornamentation of which can be used to differentiate between species. Sexual reproduction is uncommon. Asexual reproduction is accomplished through the formation of motile and nonmotile spores as well as cell division.
Classification of Golden Algae
Chrysophytes are members of the Chrysophyceae class. According to Pasher’s classification system, the Phylum Chrysophyta consists of the chrysophyceae or chrysophytes, xanthophytes (Xanthophyceae), and diatoms (Bacillariophyceae).
Chrysophyceae, as a phylum, is made up of the following orders: Chromulinales, Chrysosphaerales, Hibberdiales, Hydrurales, Phaeothamnales, and yet-to-be-classified Chrysophyceae genera. However, it should be noted that the taxonomic classification of organisms is bound to change as more studies of the species lead to a newer system of classification, such as that in The NCBI taxonomy database.
Sub-Groups
Class Chrysophyceae is comprised of the following taxonomic orders which are listed below:
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Chromulinales
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Chrysosphaerales
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Hibberdiales
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Hydrurales
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Phaeothamniales
General Characteristics
Chrysophyceae is a family of algae distinguished primarily by their flagellar structure (although there are also species that are non-motile). The majority of them have two flagella. One of them is active and possesses mastigonemes. It accounts for forward motion. The other flagellum is smooth and uninteresting. It is pointing in the opposite direction. The pigment fucoxanthin is abundant, which accounts for the golden colour. They have a globose statocyst with a single pore (also called stomatocyte). Myxochrysis paradoxa, for example, has a complicated life cycle. They have a plasmodial (amoeboid) stage in addition to the flagellate stage.
Evolution
The golden algae are thought to have evolved from earlier algal species that had undergone endosymbiotic events. Their ability to photosynthesize could be attributed to an endosymbiotic relationship with fucoxanthin-containing cyanobacteria.
Ecology
The majority of the alga gold species are freshwater species. They are mostly found in rivers and lakes. Prymnesium parvum is a golden algal species linked to harmful algal blooms caused by accelerated algal growth. When the conditions favour rapid algal growth and reproduction, this species is known to produce toxins that can kill fish. Nonetheless, there is no evidence that golden algal toxins pose a direct threat to humans or other mammals through the consumption of dead fish.
What are Desmids Golden Algae?
Desmids are also known as golden algae or golden-brown algae because of their distinctive golden colour, which is caused by the pigment fucoxanthin and the use of oil droplets as food reserves.
Many of these algae are also encased in a silica cyst ornamentation, this silica cyst is known as statocyst or also known as the statospore. This class of algae includes approximately 33 different genera and 1200 different species. They are commonly found in both fresh as well as in salt water.
Chrysophyceae, the Golden Algae
The Chrysophyceae, also known as golden algae, are common plankton components in oligotrophic lakes. They have two flagella, and most species can switch between photosynthesis and ingesting smaller organisms or particles for food.
What is the Golden Algae Bloom?
Prymnesium parvum (golden alga) is a single-celled organism that lives in water. It is found all over the world, primarily in coastal waters, but also in rivers and lakes. This alga does not always cause problems, but when it “blooms” (goes through a period of rapid growth and reproduction), it can produce toxins that kill fish. Toxins affect all gill-breathing organisms, including all the various types of fish, freshwater mussels as well clams, and the gill-breathing juvenile stage of frogs and other amphibians.
Where and When Does it Occur?
In Texas, fish kills caused by golden algae have occurred in inland waters with high salt or mineral content, usually west of I-35. The first confirmed case occurred in 1985 on the Rio Grande Basin’s Pecos River. Since then, golden alga has caused numerous fish kills in five river basins. A bloom at the Dundee State Fish Hatchery in 2001 wiped out an entire season’s worth of striped and hybrid striped bass production. In recent years, more than 20 other states have reported blooms.
A fish kill caused by golden algae can last for days, weeks, or months. Only a portion of a lake is sometimes affected, but the location can change from day to day. Blooms are more likely to occur in cold weather, and they sometimes fade as the water warms and other algae species become more active — but not always. An extended kill can have long-term consequences for a fishery and cause financial hardship for parks and businesses that cater to recreational anglers.