Cladophora is a genus of reticulated filamentous green algae in the class Ulvophyceae. They may be referred to as reticulated algae, branching algae, [1] or blanket weed. [2] The genus has a worldwide distribution and is harvested for use as a food and medicine.
Cladophora coloring is bright green which reflects the chlorophyll a, and chlorophyll b, which are similar to higher plant ratios and that also contains β-carotene and xanthophylls. [3] The thallus branches are smaller than the main axis, dichotomous, rough in texture, and have narrow tips.
Temperature, water currents and waves affect their metabolism and morphology, and branching patterns. At 15–20 °C branches appear alternate, they can also appear completely absent in temperatures below 25 °C. [3]
Cladophora form a branched filamentous chlorophyte structure with large cylindrical cells forming long, regularly branched growths. The filaments can be quite long and may form dense mats or tufts in aquatic environments. When Cladophora becomes detached from the rocky substrate that it grows upon, it can then build up on shorelines, making their reticular formations, (dense mats) visible to onlookers. When dense mats form, this can affect light penetration and oxygen levels in aquatic ecosystems. Mats may also serve as habitat and food for various aquatic organisms. [3]
The cells within Cladophora have multiple pyrenoids, are large and multiple nucleated and have many parietal round chloroplasts, which usually join into a net-like reticular formation.[ citation needed ] Thick walls called akinetes are made out of vegetative cells in times of short photoperiods, low temperatures or nutrient unavailability. The cell walls of Cladophora species often contain cellulose and pectin, providing strength and flexibility. [3] Thick walls and sheaths are mucilaginous.
 |
This plant is annual and can reproduce through both sexual and asexual mechanisms. Some species have isogametic capacities but little is known about this and it seems to be a rare occurrence present in few species. The few cases that have occurred were in apical and sub apical un-specialized cells. Cladophora generally reproduces asexually using 2 flagellated zoospores using mitotic division and distal cells of side branches.
This occurs when the male and female gametes fuse, usually in water. The fusion of gametes results in the formation of a diploid zygote. The diploid zygote undergoes mitotic divisions to form a diploid sporophyte. The sporophyte phase is often short-lived and less conspicuous. It produces haploid spores through meiosis. Haploid spores are released from the sporophyte and can be dispersed by water currents or other means. Haploid spores germinate to form new haploid gametophytes, completing the life cycle. Reproductive cells, often referred to as zoospores, are typically motile and possess flagella, allowing them to move in water.
Unlike Spirogyra the filaments of Cladophora branch and do not undergo conjugation.
There are two multicellular stages in its life cycle – a haploid gametophyte and a diploid sporophyte – which look highly similar. The only way to tell the two stages apart is to either count their chromosomes, or examine their offspring. The haploid gametophyte produces haploid gametes by mitosis and the diploid sporophyte produces haploid spores by meiosis. The only visible difference between the gametes and spores of Cladophora is that the gametes have two flagella and the spores have four.
Cladophora exist in multiple ecosystems which include both tropical and moderate climates, freshwater, wastewater, and marine water ecosystems, and in multiple biomes which include lakes, ponds, dam reservoirs, large rivers and the coastal littoral zones as well as in areas of oceanic depth (which determines temperatures and light availability as well as oxygen availability, which can become a limiting factor). This taxon needs nitrates, and orthophosphates, as well as hard water conditions with pH levels between 7–10, high light intensity and nutrient densities that are rich in nature. Cladophora may attach to submerged surfaces like rocks or other aquatic substrates, enabling it to grow more rapidly through optimization of space availability, (another limiting factors and source of infraspecific, intraspecies and interspecies competition).
In Europe, only 15 known subtypes of Cladophora are freshwater. Cladophora exists in Africa, Asia, the Pacific Islands, Australia, Europe, the Atlantic Islands, North America, New Zealand, as well as the Caribbean. In some Asian countries, almost 5% of human diets are algae, and its consumption is popular in France, Thailand, as well as the Hawaiian Islands. [3]
Cladophora balls are formed from the filaments of the algae [4] which are photosynthetic. Large numbers of these balls were thrown ashore in Devon, England. They had an average diameter of 2.5 cm and several million balls were found forming a layer. [5]
The genus Cladophora is cosmopolitan and accordingly infestations cannot often be regarded logically as being invasive. Where they occur they may at various times be seen as beneficial, as a nuisance, or an outright pest.[ citation needed ]
Modest growth of Cladophora is generally harmless; the growth is an important food for many fish and other aquatic animals, as a buffer for the sequestration of nutrients in the water body and for protection of some aquatic organisms from solar ultraviolet radiation.[ citation needed ]Cladophora species can be an environmental nuisance, however, causing major alterations to benthic conditions linked particularly with increased phosphorus loading. [3]
Where Cladophora becomes a pest is generally where special circumstances cause such drastic overgrowth that algal blooms develop and form floating mats. Typical examples include where hypertrophication or high mortality of rival organisms produce high concentrations of dissolved phosphorus. Extensive floating mats prevent circulation that is necessary for the aeration of deeper water and, by blocking the light, they kill photosynthesising organisms growing beneath. The mats interfere with the fishing industry by clogging nets and preventing the use of lines. Where they wash ashore the masses of rotting material reduce shoreline property values along water bodies such as the Great Lakes in the United States. [6]
Quagga mussel populations have increased tremendously during the same time frame as the blooming of Cladophora, though their ecological relationships are not yet clear and may be complex. [7]
Some Cladophora species, including Cladophora fascicularis, have been investigated for their use in phytoremediation. Cladophorafascicularis may contribute to improving water quality in contaminated aquatic ecosystems. This algae is biologically active. Cladophora possesses unprecedented capacities to filter toxins from water such as heavy metals and pollutants and efficiently absorb nutrients, including nitrogen and phosphorus. [3]
Cladophora is known for its blooming activities which are seasonal, (early spring to summer) and indicate their eutrophic abilities as well as that pollution may be present in the environment that they are growing within. [3]
Cladophora can be eaten as a food item either dried or fresh, however it loses some of its nutritional value with increased processing and with genetic modification. It is considered a carbohydrate when consumed. [3]
In Laos, Cladophora are commonly eaten as a delicacy and usually known in English under the name "Mekong weed". The algae grow on underwater rocks and thrive in clear spots of water in the Mekong river basin. They are harvested 1 to 5 months a year and most often eaten in dry sheets similar to Japanese nori, though much cruder in their format. Luang Prabang's speciality is dry khai with sesame (kaipen), while Vang Vieng is famous for its roasted kháy sheets. They can be eaten in strips as an appetizer, with a meal or as a snack with Beer Lao. Luang Prabang kháy sheets kaipen are the most readily available form of Mekong weed and are famous throughout the country and in the neighbouring Isaan, though difficult to find beyond Vientiane. Mekong weed can also be eaten raw, in soups, or cooked in steamed curries.[ citation needed ]
Trans-esterification of Cladophora can be used to transform it into biodiesel. Alcohols and enzymes and Cladophora oils are used to form this reaction, but production is often highly dependent on oil content. [3]
Cladophora has pharmacological uses as medication. Cladophora is purported to have antimicrobial, antihistamine, antiviral, antioxidant, anti-sclerosis, anti-inflammatory and weight loss properties as well as secondary metabolites and bioactive components that have uses in diabetes, hypertension, cancer, and serves as a protection from parasites. However, as of December 2023, Cladophora has yet to be utilized commercially as a pharmacological agent. [3]
There is an additional demand for Cladophora for biomass productivity with utilization commercially as material for value added products. It can be used for cosmetic application and used as a fertilizer. [3] Marimo used to be classified in Cladophora, though is now called Aegagropila linnaei. Algae balls are significant in the hobby aquarium trade.[ citation needed ]
Cladophora is a green macroalgae alga classified within the Chlorophyta division. Cladophora has over 183 species within its genus that are very hard to tell apart and classify, mainly because of the great variation in their appearances, which is affected by habitat, age and environmental conditions. [8]
Some species include:
Aegagropila linnaei (marimo) was formerly placed here as Cladophora aegagropila.
A gametophyte is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the sexual phase in the life cycle of plants and algae. It develops sex organs that produce gametes, haploid sex cells that participate in fertilization to form a diploid zygote which has a double set of chromosomes. Cell division of the zygote results in a new diploid multicellular organism, the second stage in the life cycle known as the sporophyte. The sporophyte can produce haploid spores by meiosis that on germination produce a new generation of gametophytes.
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, fungi and protozoa. They were thought to have appeared as early as the mid-late Ordovician period as an adaptation of early land plants.
Alternation of generations is the predominant type of life cycle in plants and algae. In plants both phases are multicellular: the haploid sexual phase – the gametophyte – alternates with a diploid asexual phase – the sporophyte.
Bryophytes are a group of land plants, sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants (embryophytes): the liverworts, hornworts, and mosses. In the strict sense, the division Bryophyta consists of the mosses only. Bryophytes are characteristically limited in size and prefer moist habitats although some species can survive in drier environments. The bryophytes consist of about 20,000 plant species. Bryophytes produce enclosed reproductive structures, but they do not produce flowers or seeds. They reproduce sexually by spores and asexually by fragmentation or the production of gemmae. Though bryophytes were considered a paraphyletic group in recent years, almost all of the most recent phylogenetic evidence supports the monophyly of this group, as originally classified by Wilhelm Schimper in 1879. The term bryophyte comes from Ancient Greek βρύον (brúon) 'tree moss, liverwort' and φυτόν (phutón) 'plant'.
Gametogenesis is a biological process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes. Depending on the biological life cycle of the organism, gametogenesis occurs by meiotic division of diploid gametocytes into various gametes, or by mitosis. For example, plants produce gametes through mitosis in gametophytes. The gametophytes grow from haploid spores after sporic meiosis. The existence of a multicellular, haploid phase in the life cycle between meiosis and gametogenesis is also referred to as alternation of generations.
The embryophytes are a clade of plants, also known as Embryophyta or land plants. They are the most familiar group of photoautotrophs that make up the vegetation on Earth's dry lands and wetlands. Embryophytes have a common ancestor with green algae, having emerged within the Phragmoplastophyta clade of freshwater charophyte green algae as a sister taxon of Charophyceae, Coleochaetophyceae and Zygnematophyceae. Embryophytes consist of the bryophytes and the polysporangiophytes. Living embryophytes include hornworts, liverworts, mosses, lycophytes, ferns, gymnosperms and angiosperms. Embryophytes have diplobiontic life cycles.
In biology, a biological life cycle is a series of stages of the life of an organism, that begins as a zygote, often in an egg, and concludes as an adult that reproduces, producing an offspring in the form of a new zygote which then itself goes through the same series of stages, the process repeating in a cyclic fashion.
The green algae are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as a sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid (spherical), and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae, many of which live most of their lives as single cells, while other species form coenobia (colonies), long filaments, or highly differentiated macroscopic seaweeds.
A sporophyte is the diploid multicellular stage in the life cycle of a plant or alga which produces asexual spores. This stage alternates with a multicellular haploid gametophyte phase.
Non-vascular plants are plants without a vascular system consisting of xylem and phloem. Instead, they may possess simpler tissues that have specialized functions for the internal transport of water.
Marimo is a rare growth form of Aegagropila linnaei in which the algae grow into large green balls with a velvety appearance.
A prothallus, or prothallium, is usually the gametophyte stage in the life of a fern or other pteridophyte. Occasionally the term is also used to describe the young gametophyte of a liverwort or peat moss as well. In lichens it refers to the region of the thallus that is free of algae.
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Asexual reproduction produces new individuals without the fusion of gametes, resulting in clonal plants that are genetically identical to the parent plant and each other, unless mutations occur.
Dictyotales is a large order in the brown algae containing the single family Dictyotaceae. Members of this order generally prefer warmer waters than other brown algae, and are prevalent in tropical and subtropical waters thanks to their many chemical defenses to ward off grazers. They display an isomorphic haplodiploid life cycle and are characterized by vegetative growth through a single apical cell. One genus in this order, Padina, is the only calcareous member of the brown algae.
Postelsia palmaeformis, also known as the sea palm or palm seaweed, is a species of kelp and classified within brown algae. It is the only known species in the genus Postelsia. The sea palm is found along the western coast of North America, on rocky shores with constant waves. It is one of the few algae that can survive and remain erect out of the water; in fact, it spends most of its life cycle exposed to the air. It is an annual, and edible, though harvesting of the alga is discouraged due to the species' sensitivity to overharvesting.
The genus Umbraulva, which is a green alga within the Ulvaceae family, was proposed by Bae and Lee in 2001. Three additional species, including U. kuaweuweu, which was subsequently transferred to another genus, have been added to the genus since it originally had the three species that were initially examined to form the genus. Umbraulva species grow upon hard substrates, and inhabit deep subtidal areas. Species within this genus are widely distributed, and have been identified in Asia, Europe, Hawaii, and New Zealand. The morphological traits of Umbraulva vary among species, but commonly, Umbraulva are macroscopic with olive green blades containing the photosynthetic pigment siphonaxanthin. The blades are flattened and ellipsoid in shape, or are narrow and oval shaped, with perforations and/or lobes present throughout the blade. As Umbraulva often appear very similar in morphology to closely related groups, the main manner in which Umbraulva was differentiated from related groups was through the divergence of ITS and partial SSU rDNA sequences from those of other Ulva species. Umbraulva is closely related to Ulva, which due to wide distributions, high carbohydrate levels, and a lack of lignin, is a good candidate for use in biofuel, bioremediation, carbon sequestration, and animal feed production.
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes (diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes.
Ulva linza is a green alga in the family Ulvaceae that can be found in British Isles.
Allomyces is a genus of fungi in the family Blastocladiaceae. It was circumscribed by British mycologist Edwin John Butler in 1911. Species in the genus have a polycentric thallus and reproduce sexually or asexually by zoospores that have a whiplash-like flagella. They are mostly isolated from soils in tropical countries, commonly in ponds, rice fields, and slow-moving rivers.
Dicranoloma billardierei is a species of bryophyte in the genus Dicranoloma. This moss is extremely common in wet rainforest habitats. In the field, Dicranoloma billardierei, is often confused with Dicranoloma robustum and Dicranoloma fasciatum. However, the short and obtuse nature of the leaves make this moss normally very distinctive.
| Authority control databases: National |
|---|
