The Red algae (or Rhodophyta, pronounced /roʊˈdɒfɨtə, ˌroʊdəˈfaɪtə/, from Greek Greek , an independent branch of the Indo-European family of languages, is the language of the Greeks. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. In its ancient form, it is the language of classical ancient Greek literature and the New Testament of: ῥόδον (rhodon) = rose + φυτόν (phyton) = plant, thus red plant) are one of the oldest groups of eukaryotic A eukaryote is an organism whose cells contain complex structures enclosed within membranes. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear envelope, within which the genetic material is carried. The presence of a nucleus gives eukaryotes their name, which comes from the algae,[2] and also one of the largest, with about 5,000–6,000 species [3] of mostly multicellular Multicellular organisms are organisms that consist of more than one cell. Each cell is specialized to do a certain job for that organism. Most life that can be seen with the naked eye is multicellular, as are all members of the kingdoms Plantae and Animalia, marine An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface (~3.61 X 1014 m2) is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas algae Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. The US Algal Collection is represented by almost 300,000 accessioned and inventoried herbarium specimens. The largest and most complex marine forms are called, including many notable seaweeds Seaweed is a loose, colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae. Seaweeds can also be classified by use. Other references indicate 10,000 species. [4]
The red algae form a distinct group characterized by the following attributes: eukaryotic cells without flagella A flagellum is a tail-like projection that protrudes from the cell body of certain prokaryotic and eukaryotic cells, and functions in locomotion. There are some notable differences between prokaryotic and eukaryotic flagella, such as protein composition, structure, and mechanism of propulsion. An example of a flagellated bacterium is the ulcer- and centrioles A centriole is a barrel-shaped cell structure found in most animal eukaryotic cells, though absent in higher plants and most fungi. The walls of each centriole are usually composed of nine triplets of microtubules . Deviations from this structure include Drosophila melanogaster embryos, with nine doublets, and Caenorhabditis elegans sperm cells, using floridean starch as food reserve, with phycobiliproteins Phycobiliproteins are water-soluble proteins present in cyanobacteria and certain algae that capture light energy, which is then passed on to chlorophylls during photosynthesis. Phycobiliproteins are formed of a complex between proteins and covalently bound phycobilins that act as chromophores (the light-capturing part). They are most important as accessory pigments (giving them their red color), and with chloroplasts Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis lacking external endoplasmic reticulum The endoplasmic reticulum is an eukaryotic organelle that forms an interconnected network of tubules, vesicles, and cisternae within cells. Rough endoplasmic reticulums synthesize proteins, while smooth endoplasmic reticulums synthesize lipids and steroids, metabolize carbohydrates and steroids, and regulate calcium concentration, drug and containing unstacked thylakoids A thylakoid is a membrane-bound compartment inside chloroplasts and cyanobacteria. They are the site of the light-dependent reactions of photosynthesis. The word "thylakoid" is derived from the Greek thylakos, meaning "sac". Thylakoids consist of a thylakoid membrane surrounding a thylakoid lumen. Chloroplast thylakoids. [4] Most red algae are also multicellular Multicellular organisms are organisms that consist of more than one cell. Each cell is specialized to do a certain job for that organism. Most life that can be seen with the naked eye is multicellular, as are all members of the kingdoms Plantae and Animalia, macroscopic, marine, and have sexual reproduction.
Many of the coralline algae Coralline algae are red algae in the Family Corallinaceae of the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. The colors of these algae are most typically pink, or some other shade of red, but some species can be purple, yellow, blue, white or gray-green, which secrete calcium carbonate Calcium carbonate is a chemical compound with the chemical formula Ca and play a major role in building coral reefs Coral reefs are underwater structures made from calcium carbonate secreted by corals. Corals are colonies of tiny living animals found in marine waters containing few nutrients. Most coral reefs are built from stony corals, and are formed by polyps that live together in groups. The polyps secrete a hard carbonate exoskeleton which provides support, belong here. Red algae such as dulse Palmaria palmata Kuntze, also called dulse, dillisk, dilsk or creathnach, is a red alga (Rhodophyta) previously referred to as Rhodymenia palmata (Linnaeus) Greville. It grows on the northern coasts of the Atlantic and Pacific oceans. It is a well-known snack food, and in Iceland, where it is known as söl, it has been an important source of fibre (Palmaria palmata) and laver Laver is an edible seaweed that has a high mineral salt content, particularly iodine and iron. It is used for making laverbread, a traditional Welsh dish, as well as eaten as a complement to rice in Japan and Korea (where it is called kim or gim). Particularly in Korea, it is sometimes roasted with sesame oil and further flavored with salt and (nori Nori is the Japanese name for various edible seaweed species of the red alga Porphyra including most notably P. yezoensis and P. tenera, sometimes called laver. Finished products are made by a shredding and rack-drying process that resembles papermaking. Japan, Korea, and China are the current major producers of nori, with total production valued/gim Gim , spelled as kim, is a Korean-style edible seaweed in the genus Porphyra, similar to the Welsh-style laver and Japanese-style nori) are a traditional part of European European cuisine, or alternatively Western cuisine, is a generalized term collectively referring to the cuisines of Europe and other Western countries. European cuisine includes that of Europe and to some extent Russia, as well as non-indigenous cuisines of North America, Australasia, Oceania, and Latin America. The term is used by East Asians to and Asian cuisine Asian cuisine styles can be broken down into several regional styles that have roots in the peoples and cultures of those regions. The major types can be roughly defined as East Asian with its origins in Imperial China and now encompassing modern Japan and the Korean peninsula; Southeast Asian which encompasses Cambodia, Laos, Thailand, Viet Nam, and are used to make other products like agar Agar or agar-agar is a gelatinous substance derived from red algae. Historically and in a modern context, it is chiefly used as an ingredient in desserts throughout Asia and also as a solid substrate to contain culture medium for microbiological work. The gelling agent is an unbranched polysaccharide obtained from the cell walls of some species of, carrageenans Carrageenans or carrageenins are a family of linear sulfated polysaccharides which are extracted from red seaweeds and other food additives Food additives are substances added to food to preserve flavor or enhance its taste and appearance. Some additives have been used for centuries; for example, preserving food by pickling , salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines. With the advent of processed foods in the second half of the 20th century,. [5]
The first red algae to have its genome sequenced was Cyanidioschyzon merolae.
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Fossil record
The oldest fossil identified as a red alga is also the oldest fossil eukaryote A eukaryote is an organism whose cells contain complex structures enclosed within membranes. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear envelope, within which the genetic material is carried. The presence of a nucleus gives eukaryotes their name, which comes from the that belongs to a specific modern taxon A taxon is a group of (one or more) organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement. Defining what belongs or does not belong to such a taxonomic group is done by a taxonomist. It is not uncommon for one taxonomist to disagree with another on what exactly belongs to. Bangiomorpha pubescens, a multicellular fossil from arctic Canada The land occupied by Canada was inhabited for millennia by various groups of Aboriginal peoples. Beginning in the late 15th century, British and French expeditions explored, and later settled, along the Atlantic coast. France ceded nearly all of its colonies in North America in 1763 after the Seven Years' War. In 1867, with the union of three, strongly resembles the modern red alga Bangia despite occurring in rocks dating to 1200 million years ago. [1]
Red algae are important builders of limestone Limestone is a sedimentary rock composed largely of the mineral calcite . Like most other sedimentary rocks, limestones are composed of grains; however, most grains in limestone are skeletal fragments of marine organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids, intraclasts, and extraclasts reefs. The earliest such coralline algae, the solenopores, are known from the Cambrian The Cambrian is the first geological period of the Paleozoic Era, lasting from 542 ± 0.3 million years ago to 488.3 ± 1.7 million years ago(ICS, 2004,; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the classical name for Period. Other algae of different origins filled a similar role in the late Paleozoic The Paleozoic or Palaeozoic Era (from the Greek palaios , "old" and zoe (ζωή), "life", meaning "ancient life") is the earliest of three geologic eras of the Phanerozoic Eon. The Paleozoic spanned from roughly 542 to 251 million years ago (ICS, 2004), and is subdivided into six geologic periods; from oldest to, and in more recent reefs.
There are also calcite Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (Ca crusts, which have been interpreted as the remains of coralline red algae dating to the terminal Proterozoic The Proterozoic is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek "earlier life". The Proterozoic Eon extended from 2500 Ma to 542.0 ± 1.0 Ma (million years ago), and is the most recent part of the old, informally named ‘Precambrian’ time.[6] Thallophytes resembling coralline red algae are known from the late Proterozoic Doushantuou formation.[7]
Taxonomy
The red algae are classified in the Archaeplastida The Archaeplastida are a major group of eukaryotes, comprising the red and green algae and the land plants, together with a small group called the glaucophytes. The plastids of all of these organisms are surrounded by two membranes, suggesting they developed directly from endosymbiotic cyanobacteria. In all other groups, plastids are surrounded by, along with the glaucophytes The glaucophytes, also known as glaucocystophytes or glaucocystids, are a small group of freshwater microscopic algae. Together with the red algae and green algae plus land plants (Viridiplantae or Chloroplastida), they form the Archaeplastida. However, the relationships between the red algae, green algae and glaucophytes are unclear, in large and Viridiplantae Viridiplantae are a clade comprising the green algae and land plants (green algae and land plants).
Below are two valid published taxonomies of the red algae, although neither necessarily has to be used, as the taxonomy of the algae is still in a state of flux (with classification above the level of order The Latin suffix -formes meaning "having the form of" is used for the scientific name of orders of birds and fishes, but not for those of mammals and invertebrates having received little scientific attention for most of the 20th century).[8] If one defines the kingdom Plantae to mean the Archaeplastida, the red algae will be part of that kingdom; but if Plantae are defined more narrowly, to be the Viridiplantae, then the red algae might be considered their own kingdom[8] or part of the kingdom Protista Protists are a diverse group of eukaryotic microorganisms. which include mostly unicellular organisms that do not fit into the other kingdoms. Historically, protists were treated as the kingdom Protista, which includes mostly unicellular organisms that do not fit into the other kingdoms, but this group is contested in modern taxonomy. Instead, it. The two classification systems below place the red algae in the plant kingdom.
Species of red algae
There are around 6,500 to 10,000 known species, [4][5] nearly all of which are marine, with about 200 that only live in fresh water Freshwater or fresh water is naturally occurring water on the Earth's surface in bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Freshwater is characterized by having low concentrations of dissolved salts and other total dissolved solids. The term specifically excludes seawater and. However, estimates of the number of real species vary by 100%. [4]
Some examples of species and genera of red algae are:
- Atractophora hypnoides
- Gelidiella calcicola
- Lemanea, a freshwater genus
- Palmaria palmata Palmaria palmata Kuntze, also called dulse, dillisk, dilsk, red dulse, sea lettuce flakes or creathnach, is a red alga (Rhodophyta) previously referred to as Rhodymenia palmata (Linnaeus) Greville. It grows on the northern coasts of the Atlantic and Pacific oceans. It is a well-known snack food, and in Iceland, where it is known as söl, it has, dulse
- Schmitzia hiscockiana
- Chondrus crispus Chondrus crispus, known under the common name Irish moss, or carrageen moss , is a species of red algae which grows abundantly along the rocky parts of the Atlantic coast of Europe and North America. In its fresh condition the plant is soft and cartilaginous, varying in color from a greenish-yellow, through red, to a dark purple or purplish-brown, Irish moss
- Mastocarpus stellatus
Chemistry
| Algal group | δ13C range[10] |
|---|---|
| HCO3-using red algae | −22.5‰ – −9.6‰ |
| CO2-using red algae | −34.5‰ – −29.9‰ |
| Brown algae | −20.8‰ – −10.5‰ |
| Green algae | −20.3‰ – −8.8‰ |
The δ13C values of red algae reflect their lifestyles. The largest difference results from their photosynthetic metabolic pathway: algae that use HCO3 as a carbon source have far more negative δ13C values than those that only use CO2.[10] An additional difference of about 1.71‰ separates groups intertidal from those below the lowest tide line, which are never exposed to atmospheric carbon. The latter group use the more 13C negative CO2 dissolved in sea water, whereas those with access to atmospheric carbon reflect the more positive signature of this reserve.
Morphology
Red algae have a double cell wall.[11] The outer layer are usually composed of "pectic substances", from which agar can be manufactured.[11] The internal wall is mostly cellulose.[11]
Pit connections and pit plugs
Main article: Pit connectionPit connections
Pit connections and pit plugs are unique and distinctive features of red algae that form during the process of cytokinesis following mitosis. In red algae, cytokinesis is incomplete. Typically, a small pore is left in the middle of the newly formed partition. The pit connection is formed where the daughter cells remain in contact.
Shortly after the pit connection is formed cytoplasmic continuity is blocked by the generation of a pit plug, which is deposited in the wall gap that connects the cells.
Connections between cells having a common parent cell are called primary pit connections. Because apical growth is the norm in red algae, most cells have two primary pit connections, one to each adjacent cell.
Connections that exist between cells not sharing a common parent cells are labeled secondary pit connections. These connections are formed when an unequal cell division produced a nucleated daughter cell that then fuses to an adjacent cell. Patterns of secondary pit connections can be seen in the order Ceramiales.
Pit plugs
After a pit connection is formed, tubular membranes appear. A granular protein, called the plug core, then forms around the membranes. The tubular membranes eventually disappear. While some orders of red algae simply have a plug core, others have an associated membrane at each side of the protein mass, called cap membranes. The pit plug continues to exist between the cells until one of the cells dies. When this happens, the living cell produce a layer of wall material that seals off the plug.
Function
It is thought that the pit connections function as structural reinforcement, and as an avenue for cell to cell communication and/or symplastic transport in red algae.[citation needed] While the presence of the cap membrane could inhibit this transport between cells, it has been hypothesized that the tubular plug cores serve as a means of transport.
Reproduction
The reproductive cycle of red algae may be triggered by factors such as day length.[2]
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Q. How t get rid of green hair algae and red slime algae from a reef tank?
Asked by smoken_420 - Wed Nov 7 20:23:39 2007 - - 2 Answers - 0 Comments
A. Algae is the result of to much nutrients in your system,mostly nitrates and phosphates which the green and red algae use for growth.Afew things you can do: 1: Cut back on feeding frozen foods if you do.They are high in phosphates 2:Make sure you are doing regular water changes.I do 10% per week. 3:Use a quality protein skimmer if you dont allready. 4:reduce you light cycle afew hours.No more that 10 hrs per day. 5:add some astrea or turbo snails to your tank.They love to eat algae New tanks will normally always go through 3 algea cylces.Brown/gold diatoms,then green hair and then the dreaded red/brown slime.Time will probably fix things.Try the newzealand marine society website.Lots of helpfull stuff and people to answer any questions… [cont.]
Answered by Darinz - Wed Nov 7 21:03:21 2007
