Asparagopsis armata | |
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( Diplodus vulgaris ). In the background, Asparagopsis armata | |
Scientific classification | |
(unranked): | Archaeplastida |
Division: | Rhodophyta |
Class: | Florideophyceae |
Order: | Bonnemaisoniales |
Family: | Bonnemaisoniaceae |
Genus: | Asparagopsis |
Species: | A. armata |
Binomial name | |
Asparagopsis armata | |
Synonyms | |
Falkenbergia rufolanosa |
Asparagopsis armata is a species of marine red algae, in the family Bonnemaisoniaceae. [1] English name(s) include red harpoon weed. [2] They are multicellular eukaryotic organisms. This species was first described in 1855 by Harvey, [3] an Irish botanist who found the algae on the Western Australian coast. A. armata usually develops on infralittoral rocky bottoms around the seawater surface to around 40m of depth. Marine algae like A. armata are considered "autogenic ecosystem engineers" as they are at the very bottom of the food chain and control resource availability to other organisms in the ecosystem. [4]
A. armata is a species native to southern Australia and New Zealand (Southern hemisphere) and is thought to have slowly spread to the Northern hemisphere through the Mediterranean sea, as it is highly invasive. It can now also be found along the British Isles to Senegal as well. [5] The first Mediterranean A. armata was reported in Algeria in 1923. When first found, it seemed strange to find A. armata in this location due to the high summer seawater surface temperatures along southern Mediterranean coasts. However, it was later found that the particular cool water temperatures that stay below 25 °C would allow the species to survive locally during the summer. [3]
The fully grown A. armata has sparse branches on which long stolons with harpoon-like hooks and erect shoots develop in all directions. The branches, stolons, and shoots ramify over and over again which give A. armata the thallus-like appearance. [3] The ultimate branchlets are filamentous and composed of three cell rows whereas the larger branches consist of a central medullary filament and a gelatinous matrix surrounded by a cortex 3 – 6 cells thick. [6] Gametophytes are terete and are around 200 mm in height. They form dense, pink intertwining clumps. A characteristic feature of this species is barbs, which attach the A. armata to the ocean benthic substrates. [7]
A. armata has a triphasic diplohaplontic heteromorphic life cycle. In this cycle, the three phases include: haploid carposporophyte, gametophyte and diploid zygote. Multiple phases of different morphology and ploidy contribute differently to the expansion potential of A. armata. Gametophytes of this species are microscopic carposoporophytes, which divide into tetrasporophytes that go through meiosis to be developed into the gametophyte.
A. armata has two morphologically different stages of development– the gametophyte stage and the tetrasporophyte stage.
A. armata goes through haploid and gametophytic phases in a heteromorphic diplo-haplontic life cycle. [3] The A. armata gametophyte grows into adult form and goes through fecundation to produce diploid carposporophyte; which, then, divide into tetrasporophyte that goes through meiosis to be developed into the gametophyte. [8]
The acceleration of marine biological invasions through increasing trade and travel also caused the transportation of A. armata to areas outside of their native range: Southern hemisphere. Once it is established, A. armata could rapidly spread and dominate the invaded environment without the direct intervention of human activity. [9] A. armata releases large amounts of toxic compounds to gain competitive advantage in the surrounding invaded area. [10] The impairment of invertebrates after exposure to this algal exudate is shown by significantly increased lipid (and other biochemical biomarkers) content in the organisms such as common prawn and marine snail. [10] The critical impact that the exudate of A. armata causes, via secondary metabolites, severely decreases the survival rate of various species in the rock pool native communities. [10]
As a defense mechanism against its predators, A. armata produce halogenated metabolites that chase away herbivores and prevent biofouling. These halogenated metabolites are stored as a refractile inclusion inside specialized gland cells, and are activated with Bromine.
Gland cells of A. armata can take up to 10% of the algal volume, which is a large portion of the plant. Gland cell walls are thin in order to help the transfer of metabolites to the structures that connect the gland cells to the pericentral cells. These structures are stalk-like and allow the metabolite to move to the algae's surface. [11]
In 2019, following laboratory studies on the effectiveness of Asparagopsis taxiformis in reducing ruminants' enteric methane emissions, a team from the University of California, Davis, demonstrated that a 1% inclusion of Asparagopsis armata in lactating dairy cows' feed resulted in a 67.2% decrease in methane produced. [12]
In 2021, CH4 Global became the first company in the world to be licensed by intellectual property holders FutureFeed to use Asparagopsis got livestock feed, with the aim of significantly reducing enteric methane emissions in ruminants. These licences enable CH4 Global to make methane reduction claims about the Asparagopsis in their product formulations in the New Zealand and Australian markets, [13] where the company has research and production facilities. A. armata is the dominant species of Asparagopsis in New Zealand. [14] CH4 Global worked with New Zealand’s National Institute of Water and Atmospheric Research (NIWA) to close the life cycle of the seaweed, which they accomplished in June of the same year, [15] enabling large quantities of the seaweed to be aquafarmed.
Sea Forest, based in Tasmania, Australia, and also a FutureFeed licensee, has chosen to focus exclusively on A. armata, and has worked with scientists at James Cook University, University of Tasmania, University of Technology Sydney, and University of New South Wales in Australia, and the University of Waikato in New Zealand, to find out how to trigger its reproduction. [16]
Chondrus crispus—commonly called 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 this protist is soft and cartilaginous, varying in color from a greenish-yellow, through red, to a dark purple or purplish-brown. The principal constituent is a mucilaginous body, made of the polysaccharide carrageenan, which constitutes 55% of its dry weight. The organism also consists of nearly 10% dry weight protein and about 15% dry weight mineral matter, and is rich in iodine and sulfur. When softened in water it has a sea-like odour and because of the abundant cell wall polysaccharides it will form a jelly when boiled, containing from 20 to 100 times its weight of water.
Palmaria palmata, also called dulse, dillisk or dilsk, red dulse, sea lettuce flakes, or creathnach, is a red alga (Rhodophyta) previously referred to as Rhodymenia palmata. It grows on the northern coasts of the Atlantic and Pacific Oceans. It is a well-known snack food. In Iceland, where it is known as söl[ˈsœːl̥], it has been an important source of dietary fiber throughout the centuries.
Schmitzia hiscockiana is a small, rare, red seaweed or marine alga of the phylum Rhodophyta or red algae. It was discovered and named in 1985.
Polysiphonia is a genus of filamentous red algae with about 19 species on the coasts of the British Isles and about 200 species worldwide, including Crete in Greece, Antarctica and Greenland. Its members are known by a number of common names. It is in the order Ceramiales and family Rhodomelaceae.
Conceptacles are specialized cavities of marine and freshwater algae that contain the reproductive organs. They are situated in the receptacle and open by a small ostiole. Conceptacles are present in Corallinaceae, and Hildenbrandiales, as well as the brown Fucales. In the Fucales there is no haploid phase in the reproductive cycle and therefore no alternation of generations. The thallus is a sporophyte. The diploid plants produce male (antheridia) and female (oogonia) gametangia by meiosis. The gametes are released into the surrounding water; after fusion, the zygote settles and begins growth.
In algal anatomy, a pit connection is a hole in the septum between two algal cells, and is found only in the red algae − specifically, all orders except the Porphyridiales and haploid Bangiales. They are often stoppered with proteinaceous "pit plugs". By contrast, many fungi contain septal pores − an unrelated phenomenon.
Rhodochorton is a genus of filamentous red alga adapted to low light levels. It may form tufts or a thin purple "turf" up to 5 millimetres high. The filaments branch infrequently, usually at the tips.
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.
Asparagopsis taxiformis, formerly A. sanfordiana, is a species of red algae, with cosmopolitan distribution in tropical to warm temperate waters. Researchers have demonstrated that feeding ruminants a diet containing 0.2% A. taxiformis seaweed reduced their methane emissions by nearly 99 percent.
A gonimoblast is a type of cell produced by red algae upon the fertilization of a zygotic nucleus, and involved in the formation of carpospores. The cells subsequently divide and ultimately serve as storage or generative cells. Storage cells contain starch and are multinucleate; whereas generative cells are situated further from the auxiliary cell, are uninucleate, and form the terminal lobes in the ensuing carpospores. Gonimoblasts are connected by septal pores, usually blocked by septal plugs.
Apophlaea is a genus of thalloid algae that is endemic to New Zealand. This genus has two species, both from the high intertidal zone on New Zealand's coasts. Specimens can reach around 15 cm in size. The thalli take a crustose form, but also contain upright, branching frond-like protrusions that reach 5–8 cm in height. Secondary pit connections and secondary pit connectionsare present in the organisms. Apophlaea reproduces by means of conceptacles; it produces tetraspores.
Amphiroa is a genus of thalloid red algae under the family Corallinaceae.
Jania is a genus of red macroalgae with hard, calcareous, branching skeletons in the family Corallinaceae.
Cordylecladia erecta is a species of red algae in the family Rhodymeniaceae. It is found in the north east Atlantic Ocean and the Mediterranean Sea and is the type species of the genus.
Asparagopsis is a genus of edible red macroalgae (Rhodophyta). The species Asparagopsis taxiformis is found throughout the tropical and subtropical regions, while Asparagopsis armata is found in warm temperate regions. Both species are highly invasive, and have colonised the Mediterranean Sea. A third accepted species is A. svedelii, while others are of uncertain status.
Batrachospermaceae is a family of fresh water red algae (Rhodophyta). Genera within the Batrachospermaceae generally have a "Lemanea-type" life history with carpospores germinating to produce chantransia. Sporophyte phase with meiosis occurs in an apical cell to produce the gametophyte stage. Pit connections have two pit plug cap layers with the other layer enlarged. This family of freshwater red algae is uniaxial, meaning each filament with a single apical cell. The genera included within Batrachospermaceae are listed in the table below.
FutureFeed is a seaweed-based feed ingredient for livestock that is currently being developed by a team from Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO). The primary component of FutureFeed is dried Asparagopsis, a genus of red algae, which has been shown to reduce the methane (CH4) emissions of ruminant livestock by up to 99%. It is added to fodder at feedlots in dosages of 1-2% dietary intake to achieve this result. FutureFeed is currently being developed in collaboration with James Cook University (JCU) and Meat and Livestock Australia (MLA), with the primary goal of scaling for mainstream commercial use.
Timothy John Entwisle, is an Australian botanist, much of whose research work is in phycology (algae). See for example the articles. He was awarded a Ph.D. from La Trobe University in 1986 for work on the taxonomy of Vaucheria.
Crustaphytum is a genus of red alga first discovered in Taoyuan algal reefs by Taiwanese scientists. The epithet “crusta” refers to crustose thallus and “phytum” refers to plant. Belonging to the family Hapalidiaceae in the order Hapalidiales, Crustaphytum is one kind of crustose coralline algae.
Naccariaceae is a family of red algae in the order Bonnemaisoniales, with 3 monotypic genera that are found in both the Pacific and Atlantic Oceans.
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