Lessonia | |
---|---|
Lessonia brevifolia | |
Scientific classification | |
Domain: | Eukaryota |
Clade: | Diaphoretickes |
Clade: | SAR |
Clade: | Stramenopiles |
Phylum: | Gyrista |
Subphylum: | Ochrophytina |
Class: | Phaeophyceae |
Order: | Laminariales |
Family: | Lessoniaceae |
Genus: | Lessonia Bory de Saint-Vincent, 1825 |
Species | |
See text |
Lessonia is a genus of large kelp native to the southern Pacific Ocean. It is the only kelp to be restricted to the southern hemisphere and is primarily distributed along the coasts of South America, New Zealand, Tasmania, and the Antarctic islands. [1] [2] Lessonia is one of two principal genera in kelp forests (the other is Macrocystis ).
In Chile, the preservation of Lessonia kelp is an important to help preserve the biodiversity that exists on rocky shores. [3] By studying the harvesting of these wild populations of Lessonia kelp marine biologists are able to analyze the effects of this activity on wildlife. [3] Some species are of economic importance, such as Lessonia nigrescens , which is harvested for alginate. [4]
They use a variety of chemical defenses and are somewhat resistant to algivory. [5] The zoospores are known to produce sporophytes even when ingested by fish. [6]
The conservation status of the genus has not been extensively researched. Only two species of Lessonia, L. oreas and L. rufa, have been assessed by the IUCN. Both of which have been marked “least concern.” [7]
The genus was first described by Jean Baptiste Bory de Saint-Vincent in 1825. [8] The genus name of Lessonia is in honour of René Primevère Lesson (1794–1849), who was a French surgeon, naturalist, ornithologist, and herpetologist. [9] The holotype for this genus is L. flavicans. [10] Recent studies have provided evidence of cryptic speciation within Lessonia including L. nigrescens in Chile [11] and L. variegata in New Zealand. [12] Lessonia is the type genus for the Lessoniaceae family. [13]
Species of Lessonia have been conflated and combined, over time, including by Bory himself, who described L. flavicans once by that name, and once by the name of L. fusceseens. [14] The former species L. laminarioides was moved to a new but related genus in 2006, Psuedolessonia. [1] Another species, L. vadosa, was proposed, but incorporated into L. flavicans. [14] [15] Other species proposed for this genus have been incorporated into Ascoseira, Himantothallus, Myriodesma, and Laminaria . [15]
Three species, L. media, L. meridionalis, and L. septentrionalis, were accepted in 2024. [13]
Several species of Lessonia are known to experience chimerism, which is when two distinct organisms fuse together to generate a new organism. Organisms that undergo chimerism will have several genomes in one body. The benefits to chimerism include an increase in body size and genetic diversity, increasing survival rates. The main cost to this would be the chance of competition between genomes. [16]
L. berteroana and L. spicata are both known to undergo chimerism.
Only the holdfast experienced genetic mixing, with the stipes each remaining genetically homogenous. [16]
Species of Lessonia are very difficult to identify based on morphological characteristics, as the kelp are very plastic. The blades may be flat and elongated, broad, or narrow, with a smooth, ruguse, or wavy surface and can have smooth or jagged edges. A big factor in the morphology is the wave exposure, as Lessonia is found across a verity of habitats. [6]
Chile is the world’s largest producer of wild-harvested algae, with Lessonia from Chile making up 29% of global exports. [17]
Chile produces over 300,000 dry tons of seaweed per year, with more than 11,000 people are employed in the industry, and almost all of it Lessonia. Almost all seaweed harvesting happens in the desert reason of Chile (18 to 32 degrees), as the climate is more suitable for drying.
Commercial brown seaweed landings started in the 1960s in Chile, but they are only included in national statistics since the 1980s. Since 2000, kelp harvesting has increased, due to an increased market demand and a decrease in the value of copper, which is the resource that makes up 60% of the Chilean GDP. In 2005, a fishing ban was enacted between 18 and 26 degrees due to concerns about over harvesting, although some studies have indicated that there are no substantial differences between the harvested and unharvested populations. L. nigresscens landings increased between 2005 and 2010, but the algal population remained strong. [18]
The Chilean seaweed corporate industry are not allowed to harvest seaweed themselves. Instead, they must purchase biomass from artisanal fishers. This means that seaweed regulations are regulated by a combination of fishers, industry, authorities, and scientists.
The other main algae harvested in Chile, L. trabeculata, is harvested by semi-autonomous divers who do not follow harvesting recommendations, causing the population to suffer. [18]
Despite New Zealand being home to six species of Lessonia, the most of any country, Lessonia harvesting is almost nonexistent. Algal cultivation has been studied in New Zealand, but rarely implemented. [19]
Several Lessonia species grow in Argentina, but the situation is similar there, with very little algae cultivation or harvesting. Part of this may be due to very little public knowledge about the option. [20]
Extensive commercial seaweed farming is done in Australia, but mostly using Asparagopsis species. [21]
Tasmania cultivated a wide variety of algae, including L. corrugata (referred to as Tasmanian Kombu). This is done with both long-line and land-based aquaculture. [22]
Peru harvests L. trabeculata, which it esports to china for processing. [23]
Kelps are large brown algae or seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant but a stramenopile.
Brown algae are a large group of multicellular algae comprising the class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, Macrocystis, a kelp of the order Laminariales, may reach 60 m (200 ft) in length and forms prominent underwater kelp forests that contain a high level of biodiversity. Another example is Sargassum, which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Some members of the class, such as kelps, are used by humans as food.
Lessoniaceae are a family of kelp. Species of this family have a transition zone with the intercalary meristem subdivided so that there are a number of secondary stipes in addition to the primary stipe.
Nereocystis is a monotypic genus of subtidal kelp containing the species Nereocystis luetkeana. Some English names include edible kelp, bull kelp, bullwhip kelp, ribbon kelp, bladder wrack, and variations of these names. Due to the English name, bull kelp can be confused with southern bull kelps, which are found in the Southern Hemisphere. Nereocystis luetkeana forms thick beds on subtidal rocks, and is an important part of kelp forests.
Ascophyllum nodosum is a large, common cold water seaweed or brown alga (Phaeophyceae) in the family Fucaceae. Its common names include knotted wrack, egg wrack, feamainn bhuí, rockweed, knotted kelp and Norwegian kelp. It grows only in the northern Atlantic Ocean, along the north-western coast of Europe including east Greenland and the north-eastern coast of North America. Its range further south of these latitudes is limited by warmer ocean waters. It dominates the intertidal zone. Ascophyllum nodosum has been used numerous times in scientific research and has even been found to benefit humans through consumption.
Laminaria is a genus of brown seaweed in the order Laminariales (kelp), comprising 31 species native to the north Atlantic and northern Pacific Oceans. This economically important genus is characterized by long, leathery laminae and relatively large size. Some species are called Devil's apron, due to their shape, or sea colander, due to the perforations present on the lamina. Others are referred to as tangle. Laminaria form a habitat for many fish and invertebrates.
Laminariaceae is a family of brown algal seaweeds, many genera of which are popularly called "kelp". The table indicates the genera within this family. The family includes the largest known seaweeds: Nereocystis and Macrocystis.
Macrocystis is a monospecific genus of kelp with all species now synonymous with Macrocystis pyrifera. It is commonly known as giant kelp or bladder kelp. This genus contains the largest of all the Phaeophyceae or brown algae. Macrocystis has pneumatocysts at the base of its blades. Sporophytes are perennial and the individual may live for up to three years; stipes/fronds within a whole individual undergo senescence, where each frond may persist for approximately 100 days. The genus is found widely in subtropical, temperate, and sub-Antarctic oceans of the Southern Hemisphere and in the northeast Pacific. Macrocystis is often a major component of temperate kelp forests.
Durvillaea is a genus of large brown algae in the monotypic family Durvillaeaceae. All members of the genus are found in the southern hemisphere, including Australia, New Zealand, South America, and various subantarctic islands. Durvillaea, commonly known as southern bull kelps, occur on rocky, wave-exposed shorelines and provide a habitat for numerous intertidal organisms. Many species exhibit a honeycomb-like structure in their fronds that provides buoyancy, which allows individuals detached from substrates to raft alive at sea, permitting dispersal for hundreds of days over thousands of kilometres. Durvillaea species have been used for clothing, tools and as a food source by many indigenous cultures throughout the South Pacific, and they continue to play a prominent role in Chilean cuisine.
Alaria is a genus of brown alga (Phaeophyceae) comprising approximately 17 species. Members of the genus are dried and eaten as a food in Western Europe, China, Korea, Japan, and South America. Distribution of the genus is a marker for climate change, as it relates to oceanic temperatures.
Durvillaea antarctica, also known as cochayuyo and rimurapa, is a large, robust species of southern bull kelp found on the coasts of Chile, southern New Zealand, and Macquarie Island. D. antarctica, an alga, does not have air bladders, but floats due to a unique honeycomb structure within the alga's blades, which also helps the kelp avoid being damaged by the strong waves.
Turbinaria is a genus of brown algae (Phaeophyceae) found primarily in tropical marine waters. It generally grows on rocky substrates. In tropical Turbinaria species that are often preferentially consumed by herbivorous fishes and echinoids, there is a relatively low level of phenolics and tannins.
Saccharina japonica is a marine species of the Phaeophyceae class, a type of kelp or seaweed, which is extensively cultivated on ropes between the seas of China, Japan and Korea. It has the common name sweet kelp. It is widely eaten in East Asia. A commercially important species, S. japonica is also called ma-konbu (真昆布) in Japanese, dasima (다시마) in Korean and hǎidài (海带) in Chinese. Large harvests are produced by rope cultivation which is a simple method of growing seaweeds by attaching them to floating ropes in the ocean.
Saccharina latissima is a brown alga, of the family Laminariaceae. It is known by the common names sugar kelp, sea belt, and Devil's apron, and is one of the species known to Japanese cuisine as kombu. It is found in the north Atlantic Ocean, Arctic Ocean and north Pacific Ocean. It is common along the coast of Northern Europe as far south as Galicia Spain. In North America, it is found on the East Coast down to Long Island, although historically extended down to New Jersey and on the West Coast down to the state of Washington. On the coast of Asia, it is found south to Korea and Japan.
Phlorotannins are a type of tannins found in brown algae such as kelps and rockweeds or sargassacean species, and in a lower amount also in some red algae. Contrary to hydrolysable or condensed tannins, these compounds are oligomers of phloroglucinol (polyphloroglucinols). As they are called tannins, they have the ability to precipitate proteins. It has been noticed that some phlorotannins have the ability to oxidize and form covalent bonds with some proteins. In contrast, under similar experimental conditions three types of terrestrial tannins apparently did not form covalent complexes with proteins.
Aquaculture of giant kelp, Macrocystis pyrifera, is the cultivation of kelp for uses such as food, dietary supplements or potash. Giant kelp contains iodine, potassium, other minerals vitamins and carbohydrates.
Lessonia nigrescens, the grey weed or giant grey weed, is a South American kelp species in the genus Lessonia.
Lessonia trabeculata is a species of kelp, a brown alga in the genus Lessonia. It grows subtidally off the coasts of Peru and northern and central Chile, with the closely related Lessonia nigrescens tending to form a separate zone intertidally. Lessonia trabeculata kelp have gained a great economic importance for alginate production, and its harvest has greatly intensified along the Chilean coast during past two decades
Medialuna ancietae is a species of sea chub native to the Pacific coast of South America where it inhabits the giant kelp forests. It is known locally as acha, mero del sur or chino.
Lessonia corrugata is a species of kelp, a brown algae in the genus Lessonia, commonly known as strapweed, common crapweed, or Tasmanian kombu. It is a subtidal species endemic to Tasmania and southern Victoria, Australia, and is the least studied of the only three Laminarian kelps in the region. The species was first described by Arthur Henry Shakespeare Lucas in 1931, and is most closely related to the New Zealand species Lessonia variegata.