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Asparagopsis | |
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Asparagopsis taxiformis in Mayotte. | |
Scientific classification ![]() | |
(unranked): | Archaeplastida |
Division: | Rhodophyta |
Class: | Florideophyceae |
Order: | Bonnemaisoniales |
Family: | Bonnemaisoniaceae |
Genus: | Asparagopsis Mont. |
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.
The genus Asparagopsis belongs to the order Bonnemaisoniales, and family Bonnemaisoniaceae. As of July 2022 [update] , there are three confirmed species: [1]
Other possible species are still unconfirmed: [1]
This genus, particularly Asparagopsis taxiformis, is also a complex species line which is composed of six cryptic lineages with different biogeographic distributions. [2]
The thalli are composed of erected feathery or plumose branches that arise from creeping stolons attached to substrate with the aid of rhizoids. The erect branches compose a central terete axis that give rise to densely arranged plumose branches. The plumose branches are composed of numerous fine, delicate, and densely determinate branchlets that are disposed around an axis. Creeping, harpoon-like barbed branchlets are uniquely found in Asparagopsis armata, which contributes to its status as one of the worst invasive species in the temperate regions. [3]
The colour of thalli ranges from red to reddish brown. Some exhibits brown colouration, especially when exposed to the tides.[ citation needed ]
The main reproductive structures are the cystocarps (female) and spermatangia (male). The cystocarps are subspherical to ovate in shape, and grow at the apices of the short branches. The structures are red in color, while the spermatangia are cylindrical in shape, and also grow at the apices. [4]
The tetrasporophyte of the genus Asparagopsis is morphologically different from the gametophyte. It exhibits a turf-like appearance, with trisophonous filaments that occur in either red or brown colouration.[ citation needed ]
It is an interesting note that the cryptic lineages of Asparagopsis taxiformis line exhibit different morphological characteristics. Morphological delineation between these genetic lineages were observed and recorded on both gametophytic and tetrasporophytic forms. Size, shape, and number of cells were compared on the thallus, reproductive structures (spermatangia and carposporophyte) of each lineage. Results show that there is a difference between these structures of A. taxiformis cryptic lineages, on which a revision of the taxonomic status of this species has been proposed. [5]
Like other seaweeds from the order Bonnemaisoniales, the life history of the genus Asparagopsis is triphasic and heteromorphic, meaning an alternation of 2 diploid and 1 haploid stage constitute the whole life cycle. Reproduction begins when the spermatium (male gamete) from the male gametophyte fertilises the carpogonium (female gamete) of the female gametophyte. This results in a developing zygote that eventually becomes a diploid carposporophyte. The carposporophyte grows along the axes of the female branch and acts as a parasite, absorbing nutrients from the female plant. Seasonal environmental conditions, such as temperature, activate the release of mature carpospores from the cystocarp. Carpospores will settle and germinate to become tetrasporophytes. Eventually, tetrasporophytes will produce tetraspores, usually in sets of four, two spores will become the male gametophyte, while the remaining two become the female gametophyte. The sex ratio is normally 50:50. [6]
The species Asparagopsis taxiformis is found throughout the tropical and subtropical regions, while Asparagopsis armata is distributed in the warm temperate region, where it clings to other seaweeds using its barbed harpoon branches. A. taxiformis typically grows on solid substrate of rocky-reef areas, from intertidal (wave and tide exposed) to subtidal areas. [7]
The genus Asparagopsis is known to be an important, highly invasive species. Both species A. armata and A. taxiformis are included on the list of the "worst invasive alien species threatening biodiversity in Europe and Mediterranean Sea". [8] Asparagopsis armata, a native species from Australia and New Zealand, has spread its population strictly in the temperate region, particularly in Europe. Due to its invasive capacity, the presence of Asparagopsis has an effect on the distribution and abundance of other marine organisms, such as peracarid crustaceans. [9]
Assemblage of epifaunal communities in the Mediterranean Sea shows a decrease in diversity and homogenised distribution compared with other associated seaweeds present in the area. The structure of the associated macrofauna (species composition, variability among samples, and relative abundance of the species) was also different in a habitat dominated by A. armata and A. taxiformis. This further validates the capacity of genus Asparagopsis to be successful and influential bio-invaders of different habitats. [10]
The genus Asparagopsis, is used as food for human consumption; for medicinal applications: antibacterial, antimicrobial, antibiotic, and goitre, among others, and cosmetics. [11] [ unreliable medical source? ] It also has the potential to be used in the development of pharmaceuticals. [12] [13]
In Hawaii, dried Asparagopsis taxiformis is considered as a delicacy, and is commonly eaten in poke (fish salad). The seaweed is prepared by cleaning and soaking it overnight in fresh water to remove the bitter iodine taste. [14]
Like all macroalgae, Asparagopsis contains bromoform, a halogen compound which is known to inhibit methane production in ruminants. It has been shown to convert much of the enteric methane (a powerful greenhouse gas) to energy (and some carbon dioxide) for cattle during normal digestion. Because of its high bromoform content, Asparagopsis has proven to be very effective in inhibiting methane production in livestock. Laboratory experiments have shown that 2-5% of seaweed biomass effectively reduces emissions by 98-100%. [15] [16] A 2020 collaborative study conducted in Australia by Meat and Livestock Australia, CSIRO and James Cook University, confirmed the effectiveness of Asparagopsis in reducing methane emissions, and also showed emissions could be reduced by more than 98% with a 0.2% addition of Asparagopsis to cattle's feed. [17] [18] Emissions were reduced by 80% when Asparagopsis accounted for 3% of the cattle's feed. [19] [20] This could address the increased carbon footprint from the meat industry and mitigate climate issues in the long run. [21]
Subsequent to the Australian study, CSIRO established FutureFeed Pty Ltd., which holds the global intellectual property (IP) rights for the use of Asparagopsis for livestock feed, with the aim of significantly reducing enteric methane emissions in ruminants. [22] In 2020, FutureFeed won a Food Planet Prize worth $1 million. [23] The importance of the product is as a food supplement. [24]
FutureFeed aims to support this use of Asparagopsis and licenses its IP accordingly. CH4 Global, with research and production facilities in Australia and New Zealand, was the first licensee. [25] Others include Sea Forest, [26] also in Australia, Symbrosia [27] and Blue Ocean Barns [28] in the USA, and Volta Greentech in Sweden. [29]
Some organizations, including CH4 Global, [30] Sea Forest, [31] Blue Ocean Barns, [32] and Greener Grazing, [33] are developing methods for the large-scale cultivation of Asparagopsis, either in land-based and ocean hatchery systems.
As interest from the investment community has grown, several companies have obtained series A venture capital financing: Blue Ocean Barns received US$20 million, [34] CH4 Global received an initial US$13 million, [35] and Symbrosia US$7 million. [36]
In 2022-23, Meat & Livestock Australia published a study of the use of Asparagopsis with canola oil as a carrier, in the "finishing diet" of penned Wagyu cattle. It resulted in a 28% reduction in methane (CH4) production. However, there was also persistently reduced liveweight, liveweight gain, and a trend to reduced carcase weight. [37]
Fodder, also called provender, is any agricultural foodstuff used specifically to feed domesticated livestock, such as cattle, rabbits, sheep, horses, chickens and pigs. "Fodder" refers particularly to food given to the animals, rather than that which they forage for themselves. Fodder includes hay, straw, silage, compressed and pelleted feeds, oils and mixed rations, and sprouted grains and legumes. Most animal feed is from plants, but some manufacturers add ingredients to processed feeds that are of animal origin.
Burping is the release of gas from the upper digestive tract of animals through the mouth. It is usually audible.
Bromoform is an organic compound with the chemical formula CHBr3. It is a colorless liquid at room temperature, with a high refractive index and a very high density. Its sweet odor is similar to that of chloroform. It is one of the four haloforms, the others being fluoroform, chloroform, and iodoform. It is a brominated organic solvent. Currently its main use is as a laboratory reagent. It is very slightly soluble in water and is miscible with alcohol, benzene, chloroform, ether, petroleum ether, acetone and oils.
Enteric fermentation is a digestive process by which carbohydrates are broken down by microorganisms into simple molecules for absorption into the bloodstream of an animal. Because of human agricultural reliance in many parts of the world on animals which digest by enteric fermentation, it is the second largest anthropogenic factor for the increase in methane emissions directly after fossil fuel use.
Ceramium is a genus of Ceramium algae. It is a large genus with at least 15 species in the British Isles.
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.
Gastroclonium reflexum is a small red alga (Rhodophyta) reported from Ireland and Britain.
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.
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of Rhodophyta (red), Phaeophyta (brown) and Chlorophyta (green) macroalgae. Seaweed species such as kelps provide essential nursery habitat for fisheries and other marine species and thus protect food sources; other species, such as planktonic algae, play a vital role in capturing carbon and producing at least 50% of Earth's oxygen.
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.
Asparagopsis armata is a species of marine red algae, in the family Bonnemaisoniaceae. English name(s) include red harpoon weed. They are multicellular eukaryotic organisms. This species was first described in 1855 by Harvey, 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.
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.
Edible seaweed, or sea vegetables, are seaweeds that can be eaten and used for culinary purposes. They typically contain high amounts of fiber. They may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae. Seaweeds are also harvested or cultivated for the extraction of polysaccharides such as alginate, agar and carrageenan, gelatinous substances collectively known as hydrocolloids or phycocolloids. Hydrocolloids have attained commercial significance, especially in food production as food additives. The food industry exploits the gelling, water-retention, emulsifying and other physical properties of these hydrocolloids.
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.
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.
The production of cattle has a significant environmental impact, whether measured in terms of methane emissions, land use, consumption of water, discharge of pollutants, or eutrophication of waterways.
The taxon Ceramium siliquosum is a small marine alga. It belongs to the red algae genus Ceramium.
FutureFeed was established by Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO), FutureFeed holds the global intellectual property for the use of Asparagopsis seaweed as a ruminant livestock feed ingredient that can reduce methane emissions by 80% or more. This result can be achieved by the addition of a small amount of the seaweed into the daily diet of livestock. This discovery was made by a team of scientists from CSIRO and James Cook University (JCU), supported by Meat & Livestock Australia (MLA), who came together in 2013 to investigate the methane reduction potential of various native Australian seaweeds.
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