Characeae

Last updated

Characeae
CharaFragilis.jpg
Chara globularis
Scientific classification OOjs UI icon edit-ltr.svg
(unranked): Viridiplantae
(unranked): Charophyta
Class: Charophyceae
Order: Charales
Family: Characeae
S.F.Gray
Genera

See text.

Characeae is a family of freshwater green algae in the order Charales, commonly known as stoneworts. They are also known as brittleworts or skunkweed, from the fragility of their lime-encrusted stems, and from the foul odor these produce when stepped on.

Contents

In some treatments, the Characeae includes all the living (extant) species of Charales; this circumscription is followed here. In other treatments, the genus Nitellopsis , which has both extant and extinct species, is placed in a separate family, Feistiellaceae.

Nitellopsis obtusa Nitellopsis obtusa.jpeg
Nitellopsis obtusa
Submerged meadow of Chara vulgaris Chara1.jpg
Submerged meadow of Chara vulgaris

Description

Living members of the Characeae sensu lato grow in freshwater and brackish environments worldwide, and have large, macroscopic thalli growing up to 120 cm long, they are branched, multicellular, and use chlorophyll to photosynthesize. Their only diploid stage in the life cycle is the unicellular oospore. They may be called stoneworts, [1] because the plants can become encrusted in lime (calcium carbonate) after some time. The "stem" is actually a central stalk consisting of giant, multinucleated cells. They are unique in having a whorl of small branchlets at each node in the stipe which gives them a superficial resemblance to the genus Equisetum . In these whorls it is possible to see the phenomenon of cytoplasmic streaming. Streaming in Chara is the fastest recorded of any cell. Cytoplasmic streaming is caused by the microfilaments found inside the cell, as proven by the use of cytochalasin B to stop streaming.[ citation needed ]

There are about 400 extant species worldwide, with 33 in Britain and Ireland according to Groves and Bullock-Webster), [2] [3] however Stewart and Church (1992) reduce this to 21. [4]

Characeae are the principal photosynthesizers of some of the volcanic crater lakes of Nicaragua, and can be found in excess of 20 meters depth in some circumstances. Introduced tilapia (Oreochromis niloticus) consumed all the Characeae in Lake Apoyo. [5]

The antheridia (or globules [6] ) and oogonia (or nucules [6] ) are protected by a layer of sterile cells when mature; the oogonium is oblong in shape and consists of a single egg, while the spherical antheridium is packed with threadlike cells that produce spermatia. As a result, the Characeae have the most complex structure of all green algae.

Genera

Genera that include extant species and are placed in a broad circumscription of the family are: [7]

Ecology

Most extant Characeae are found in fresh water, usually in still, clear water where they attach to the substrate by rhizoids. They can be pioneer colonizers or ephemerals. [9] They are usually found in low to medium nutrient-rich water and tend to disappear due to eutrophication. Some stoneworts can survive in brackish or maritime habitats and occur in ephemeral saline lakes in Australia that have twice the salinity of seawater. [10]

Related Research Articles

<span class="mw-page-title-main">Algae</span> Diverse group of photosynthetic eukaryotic organisms

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 alga 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. Algae that are carried by water are plankton, specifically phytoplankton.

<span class="mw-page-title-main">Chlorophyta</span> Phylum of green algae

Chlorophyta is a taxon of green algae informally called chlorophytes. The name is used in two very different senses, so care is needed to determine the use by a particular author. In older classification systems, it is a highly paraphyletic group of all the green algae within the green plants (Viridiplantae) and thus includes about 7,000 species of mostly aquatic photosynthetic eukaryotic organisms. In newer classifications, it is the sister clade of the streptophytes/charophytes. The clade Streptophyta consists of the Charophyta in which the Embryophyta emerged. In this latter sense the Chlorophyta includes only about 4,300 species. About 90% of all known species live in freshwater. Like the land plants, green algae contain chlorophyll a and chlorophyll b and store food as starch in their plastids.

<span class="mw-page-title-main">Charales</span> Order of green algae in the division Charophyta

Charales is an order of freshwater green algae in the division Charophyta, class Charophyceae, commonly known as stoneworts. Depending on the treatment of the genus Nitellopsis, living (extant) species are placed into either one family (Characeae) or two. Further families are used for fossil members of the order. Linnaeus established the genus Chara in 1753.

<span class="mw-page-title-main">Desmidiales</span> Order of algae

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.

<span class="mw-page-title-main">Streptophyta</span> Clade consisting of the charophyte algae and land plants

Streptophyta, informally the streptophytes, is a clade of plants. The composition of the clade varies considerably between authors, but the definition employed here includes land plants and all green algae except the Chlorophyta and the more basal Prasinodermophyta.

<span class="mw-page-title-main">Charophyta</span> Phylum of algae

Charophyta is a group of freshwater green algae, called charophytes, sometimes treated as a division, yet also as a superdivision or an unranked clade. The terrestrial plants, the Embryophyta emerged deep within Charophyta, possibly from terrestrial unicellular charophytes, with the class Zygnematophyceae as a sister group.

<span class="mw-page-title-main">Charophyceae</span> Class of algae

Charophyceae is a class of charophyte green algae. AlgaeBase places it in division Charophyta. Extant (living) species are placed in a single order Charales, commonly known as "stoneworts" and "brittleworts". Fossil members of the class may be placed in separate orders, e.g. Sycidiales and Trochiliscales.

<span class="mw-page-title-main">Archaeplastida</span> Clade of eukaryotes containing land plants and some algae

The Archaeplastida are a major group of eukaryotes, comprising the photoautotrophic red algae (Rhodophyta), green algae, land plants, and the minor group glaucophytes. It also includes the non-photosynthetic lineage Rhodelphidia, a predatorial (eukaryotrophic) flagellate that is sister to the Rhodophyta, and probably the microscopic picozoans. The Archaeplastida have chloroplasts that are surrounded by two membranes, suggesting that they were acquired directly through a single endosymbiosis event by feeding on a cyanobacterium. All other groups which have chloroplasts, besides the amoeboid genus Paulinella, have chloroplasts surrounded by three or four membranes, suggesting they were acquired secondarily from red or green algae. Unlike red and green algae, glaucophytes have never been involved in secondary endosymbiosis events.

<i>Lemanea</i> Genus of algae

Lemanea is a genus of freshwater red algae, in the order Batrachospermales. Both species are considered to be widespread in the northern hemisphere. Although placed in the Rhodophyta it in fact is green in colour.

<i>Draparnaldia</i> Genus of algae

Draparnaldia is a genus of freshwater green algae in the family Chaetophoraceae. Draparnaldia are uniseriate; each filament is composed of a chain of cells arranged in one row. Chloroplasts appear as a band within the center of each cell. The length of the main axis cells are generally the same, regardless of whether or not they bear branches. These side branches are divided extensively into terminal hairs. The entire plant is enveloped in loose, slippery mucilage. Draparnaldia is a cosmopolitan genus with wide distribution and it is usually found in cold aerated waters. They are either attached to sand or grow epiphytically on other aquatic plants. Draparnaldia can be seen growing in clear streams trailing on stones and boulders. Herman S. Forest of The Southern Appalachian Botanical Club has stated that while not common, it is present frequently enough to be recorded in almost all local flora lists of green algae that have been compiled. A multitude of species are present in Lake Baikal, Siberia and have been described by Meyer and Jasnitzky. A species of the genus had been placed and described in the Linnean Herbarium as Conferva mutabilis Roth in 1797. Nowadays Conferva is no longer used and the species is described as Draparnaldia mutabilis (Roth) Bory. Bory is added in honour of the researcher of the same name, based on whose description the genus was separated from similar appearing forms. Bory is accredited with the establishment of the genus.

The Mesostigmatophyceae are a class of basal green algae found in freshwater. In a narrow circumscription, the class contains a single genus, Mesostigma. AlgaeBase then places the order within its circumscription of Charophyta. A clade containing Chlorokybus and Spirotaenia may either be added, or treated as a sister, with Chlorokybus placed in a separate class, Chlorokybophyceae. When broadly circumscribed, Mesostigmatophyceae may be placed as sister to all other green algae, or as sister to all Streptophyta.

<span class="mw-page-title-main">Zygnematophyceae</span> Class of algae

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 land plants.

<i>Chara</i> (alga) Genus of green algae

Chara is a genus of charophyte green algae in the family Characeae. They are multicellular and superficially resemble land plants because of stem-like and leaf-like structures. They are found in freshwater, particularly in limestone areas throughout the northern temperate zone, where they grow submerged, attached to the muddy bottom. They prefer less oxygenated and hard water and are not found in waters where mosquito larvae are present. They are covered with calcium carbonate (CaCO3) deposits and are commonly known as stoneworts. Cyanobacteria have been found growing as epiphytes on the surfaces of Chara, where they may be involved in fixing nitrogen, which is important to plant nutrition.

<span class="mw-page-title-main">Red algae</span> Division of archaeplastids

Red algae, or Rhodophyta, are one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity.

<i>Nitella</i> Genus of algae

Nitella is a genus of charophyte green algae in the family Characeae.

<i>Hildenbrandia</i> Genus of algae

Hildenbrandia is a genus of thalloid red alga comprising about 26 species. The slow-growing, non-mineralized thalli take a crustose form. Hildenbrandia reproduces by means of conceptacles and produces tetraspores.

Masashi Tazawa is a botanist, notable for his physiological, biophysical and cell biological research on characean cells. He is a member of the Botanical Society of Japan, a corresponding member of the American Society of Plant Physiologists, and an honorary member of the German Botanical Society. Tazawa is also an honorary member of The Botanical Society of Japan and also an honorary member of the Japanese Society of the Plant Physiologists. In 1990. Tazawa received the Japan Academy Prize. In 1990/91 he was president of the Japanese Society of Plant Physiologists, and from 1976 to 1981, he was secretary of the Japanese Society of Cell Biology.

<i>Nitellopsis obtusa</i> Species of plant

Nitellopsis obtusa is a large freshwater alga. It is also known by the common name starry stonewort. This alga grows to a length of over 1.5 metres, is bright translucent green and has branches growing in whorls from the main axis the plants easily break up. It is easily distinguished from other charophytes by star-shaped bulbils which permit vegetative reproduction.

The Characeae or stoneworts are a family of green algae. This is a partial list of species found in Britain and Ireland.

<span class="mw-page-title-main">Feistiellaceae</span>

Feistiellaceae is a family of freshwater green algae in the order Charales.

References

  1. Kapraun, D.F. (2007), "Nuclear DNA content estimates in green algal lineages: chlorophyta and streptophyta", Ann. Bot., 99 (4): 677–701, doi:10.1093/aob/mcl294, PMC   2802934 , PMID   17272304
  2. Groves, J. & Bullock-Webster, G.R. (1920), The British Charophyta. Vol. 1, Nitelleae, London: The Ray Society, OCLC   504031618
  3. Groves, J. & Bullock-Webster, G.R. (1924), The British Charophyta. Vol.2, Chareae, London: The Ray Society, OCLC   928852232
  4. Stewart, N.F. & Church, J.M. (1992), Red Data Books of Britain and Ireland, Peterborough: The Joint Nature Conservation Committee, ISBN   978-1-873701-24-9
  5. McCrary, J.K.; Murphy, B.R.; Stauffer Jr., J.R. & Hendrix, S.S. (2007), "Tilapia (Teleostei: Cichlidae) status in Nicaraguan natural waters" (PDF), Env. Biol. Fishes, 78 (2): 107–114, doi:10.1007/s10641-006-9080-x, S2CID   23302504, archived from the original (PDF) on 2011-10-03, retrieved 2011-05-31
  6. 1 2 "Structure and Reproduction in Chara - Fresh Water Green Algae", Botany Studies, 6 August 2017, retrieved 2019-09-03
  7. "Characeae Agardh", Interim Register of Marine and Nonmarine Genera (IRMNG), retrieved 2022-02-20
  8. Guiry, M.D.; Guiry, G.M., "Nitellopsis", AlgaeBase , World-wide electronic publication, National University of Ireland, Galway, retrieved 2022-02-20
  9. John, D.M.; Whitton, B.A. & Brook, A.J. (2002), The Freshwater Algal Flora of the British Isles, London: Cambridge University Press, ISBN   978-0-521-77051-4
  10. Burne, R.V.; Bauld, J. & de Decker, P. (1980), "Saline lake charophytes and their geological significance", Journal of Sedimentary Petrology, 50: 281–293, doi:10.1306/212F79D2-2B24-11D7-8648000102C1865D