These organisms are called primary because all other organisms rely on them (directly or indirectly) as a food source 29. Their plastids also contain chlorophyll c and carotenoids (the most widespread of those being fucoxanthin).[54]. To purchase short-term access, please sign in to your personal account above. Brown algae contain the photosystem 1 reaction-centre complex, a P700-chlorophyll a-protein which has similar spectroscopic and chemical properties to those of higher plants. This consumption helps keep carbon dioxide levels in check, reducing its presence as a greenhouse gas 28. Bacteria cannot use oxygen in photosynthesis, and therefore produce energy anaerobically (without oxygen) 18. 2023 Fondriest Environmental, Inc. | Questions? Web. noun : any of a group of mostly marine algae with the chlorophyll masked by brown coloring matter Medical Definition brown alga noun : any of a division (Phaeophyta) of variable mostly marine algae (as a laminaria) with chlorophyll masked by brown pigment see algin, laminarin Love words? Pneumatocysts are most often spherical or ellipsoidal, but can vary in shape among different species. Chls c differ from Chls a, b and d in being Mg-phytoporphyrins rather than Mg-chlorins. Necessary cookies are absolutely essential for the website to function properly. . But, because some botanists define "true" stems, leaves, and roots by the presence of these tissues, their absence in the brown algae means that the stem-like and leaf-like structures found in some groups of brown algae must be described using different terminology. When nutrient levels rise, phytoplankton growth is no longer nutrient-limited and a bloom may occur 13. It absorbs energy from light; this energy is then used to convert carbon dioxide . REASON: green algae contain chlorophyll a and chlorophyll b. Photosynthesis is the process by which organisms use sunlight to produce sugars for energy. These harmful algal blooms can also cause shellfish poisoning in humans and other adverse effects 13. As an example, the New Hampshire Department of Environmental Services provides the following chlorophyll guidelines for river quality: a chlorophyll measurement below 7 g/l is within a desirable range. Alberte RS, Friedman AL, Gustafson DL, Rudnick MS, Lyman H. Biochim Biophys Acta. Biochim Biophys Acta Bioenerg. They possess chlorophyll a, c, carotenoids, and xanthophylls. This complex represents about 10--20% of the total chlorophyll in all species; the Acrocarpia paniculata complex has a chlorophyll/P700 ratio of 38. How long should you meditate as a Buddhist? Within those organelles is a compound called chlorophyll. Chlorophyll A is a green pigment, which is why the majority of plants and algae and other photosynthetic organisms are green (since it's found in all organisms that photosynthesize). Elliot Walsh holds a B.S in Cell and Developmental Biology and a B.A in English Literature from the University of Rochester. The red and brown pigments just cover the chlorophyll present inside these algae Chlorophyll is green in colour. [26], In addition to alginates, fucoidan and cellulose, the carbohydrate composition of brown algae consist of mannitol, laminarin and glucan. As with other detritus (non-living organic material), the phytoplankton will be decomposed by bacteria, and the carbon is either released back into the ocean as dissolved carbon dioxide or eventually deposited into the seafloor sediment 33. Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. Updates? But opting out of some of these cookies may affect your browsing experience. 4 Do red and brown algae contain chlorophyll? Specifically, both green and blue-green algae are popular species for generation of bioproducts and biofuels due to their efficient photosynthetic pathway [3, 4]. Still, these algae look brown in colour. In coastal and open-ocean environments, oceanic circulation is responsible for phytoplankton concentrations. [15] Specifically, the brown algal cell wall consists of several components with alginates and sulphated fucan being its main ingredients, up to 40% each of them. The set of wavelengths absorbed by a pigment is its absorption spectrum. They are mostly found in marine environments. The chemical composition and the absorption rate differ in each sub-type. This cookie is set by GDPR Cookie Consent plugin. If phytoplankton concentrations are abnormally high or low for a season, it may indicate other water quality concerns that should be addressed. Before Chloroblasts that contain chlorophylls a and b give green algae their bright green color. This is why phytoplankton, particularly cyanobacteria, can thrive at the bottom of the euphotic (sunlit) zone, where only blue light can reach. Rain can contribute runoff, or encourage the mixing of nutrient-depleted and nutrient-rich layers of water. While chlorophyll measurements can be used to estimate entire phytoplankton populations en masse, the accessory pigments phycocyanin and phycoerythrin can be measured to estimate cyanobacteria concentrations specifically. Most brown algae, with the exception of the Fucales, perform sexual reproduction through sporic meiosis. These different combinations of . Chlorophyll C is found in red algae, brown algae, and dinoflagellates 15. Despite their ability to conduct photosynthesis for energy, blue-green algae are a type of bacteria. Chlorophyll is a type of pigment. In addition to chlorophyll A, blue-green algae also contain the pigments phycoerythrin and phycocyanin, which give the bacteria their bluish tint (hence the name, blue-green algae) 15. The name blade is most often applied to a single undivided structure, while frond may be applied to all or most of an algal body that is flattened, but this distinction is not universally applied. [21], Genetic and ultrastructural evidence place the Phaeophyceae among the heterokonts (Stramenopiles),[22] a large assemblage of organisms that includes both photosynthetic members with plastids (such as the diatoms) as well as non-photosynthetic groups (such as the slime nets and water molds). Blue-green algae, or cyanobacteria, are the only phytoplankton that contain phycocyanin and phycoerythrin, making the pigments good indicators of the amount of cyanobacteria in a body of water 15. At normal levels, heterotrophic bacteria in the water break down the toxins in these organisms before they can become dangerous 51. Carotenoids can be found in nearly every phytoplankton species, and reflect yellow, orange and/or red light 15. Chlorophyll B Chlorophyll B is also a green pigment, and it's found in plants and green algae. Brown algae has Chlorophyll a and c. It also has the pigment fucoxanthin responsible for it's brown color and xanthophylls. Whatever their form, the body of all brown algae is termed a thallus, indicating that it lacks the complex xylem and phloem of vascular plants. [33] Fossils of Drydenia consist of an elliptical blade attached to a branching filamentous holdfast, not unlike some species of Laminaria, Porphyra, or Gigartina. Algae obtain energy by _____. Under the right conditions, algal blooms can last one week to an entire summer, despite the short, few-day life span of phytoplankton 11. An official website of the United States government. These cookies ensure basic functionalities and security features of the website, anonymously. Only the visible light range (blue to red) is considered photosynthetically active radiation 1. It isn't found in high concentrations like chlorophyll A is, which leads scientists to believe that this is more of a "helper" pigment to increase the amount of light absorbed instead of providing a necessary role to photosynthesis. Unlike a root system, the holdfast generally does not serve as the primary organ for water uptake, nor does it take in nutrients from the substrate. [44], The earliest known fossils that can be assigned reliably to the Phaeophyceae come from Miocene diatomite deposits of the Monterey Formation in California. When carbon dioxide is consumed, the carbon molecules become incorporated into the phytoplanktons structure, allowing the organism to function and grow 11. The cookie is used to store the user consent for the cookies in the category "Analytics". This can be further classified into chlorophyll c 1, c 2 and c 3. Photosynthetic production peaks during the day and declines after dark 24. Algae is usually defined by the coloration, which can include green algae, brown algae, red algae and blue-green algae. The main advantage of sampling phytoplankton is the ability to analyze and identify the species present 41. However, most scientists assume that the Phaeophyceae evolved from unicellular ancestors. If oxygen levels get too low, fish and other aquatic creatures may die 44. Cyanobacteria are oxygenic photosynthetic bacteria. A brown pigment of the algae. These other chlorophylls still absorb sunlight, and thus assist in photosynthesis 20. Chlorophyll C is found in red algae, brown algae, and dinoflagellates 15. Does brown algae have chlorophyll a and b? Plants and phytoplankton use these three ingredients to produce glucose (sugar) and oxygen. To be considered a phytoplankton, the algae needs to use chlorophyll A in photosynthesis, be single-celled or colonial (a group of single-cells), and live and die floating in the water, not attached to any substrate 1. They can change color depending on salinity, ranging from reddish to brown. Fritsch, F. E. 1945. A high chlorophyll measurement is an indicator of eutrophication. These types have a habitat on rocky coasts in temperate zones or open seas . Fast Facts. 2008 Mar;275(6):1056-68. doi: 10.1111/j.1742-4658.2008.06262.x. In 90% acetone: Chlorophyll a (mg/L) = 11.47 (A664) - 0.4 (A630) Chlorophyll c1 + c2 (mg/L) = 24.36 (A630) - 3.73 (A664) SPECIALIZED PROCEDURES A. They are single-celled, but at times they can grow in colonies large enough to be seen by the human eye 16. The occurrence of Phaeophyceae as fossils is rare due to their generally soft-bodied nature,[31] and scientists continue to debate the identification of some finds. Let us know if you have suggestions to improve this article (requires login). There are thousands of species of planktonic algae, or microalgae, floating in water all over the world. FOIA This returned light can then be measured to determine how much chlorophyll is in the water, which in turn estimates the phytoplankton concentration. For full access to this pdf, sign in to an existing account, or purchase an annual subscription. The surface of the lamina or blade may be smooth or wrinkled; its tissues may be thin and flexible or thick and leathery. A stipe is a stalk or stemlike structure present in an alga. Following successful sign in, you will be returned to Oxford Academic. Regardless of size or form, two visible features set the Phaeophyceae apart from all other algae. Algae blooms can occur near the poles in the spring, when there is plenty of sunlight and the melting sea ice leaves behind nutrient-rich freshwater 30. diatoms and brown algae) and dinoflagellates. Further, the position of the long-wavelength emission band in brown algae and the diatom lies about 15 nm on the shorter wavelengths side than those for other classes of algae and for chloroplasts of higher plants, The form of chlorophyll a which emits long-wavelength bands is unstable and is easily destroyed by mechanical treatment of the tissue or cells of brown algae and diatoms, Action spectra of fluorescence showed that 530560 nm-light, absorbed by fucoxanthin, contributed to the emissions at 690695 nm and 705715 nm at 196C. Web Exibits: Causes of Color: Green Plants & Chlorophyll, Kimball's Biology Pages: Chlorophylls and Carotenoids, University of California Museum of Paleontology: Photosynthetic Pigments, Journal of Biological Chemistry: Chlorophyll D A Green Pigment of Red Algae, Trends in Plant Science: Chlorophyll D: The Puzzle Resolved, Texas Parks and Wildlife: Biology of Golden Alga. We also use third-party cookies that help us analyze and understand how you use this website. [26] While many carbonaceous fossils have been described from the Precambrian, they are typically preserved as flattened outlines or fragments measuring only millimeters long. [15][16] Besides fronds, there are the large in size parenchymatic kelps with three-dimensional development and growth and different tissues (meristoderm, cortex and medulla) which could be consider the trees of the sea. [6] In other species, the surface of the blade is coated with slime to discourage the attachment of epiphytes or to deter herbivores. As light is required for photosynthesis to occur, the amount of light available will affect this process. Marine phytoplankton are mainly comprised of microalgae known as dinoflagellates and diatoms, though other algae and cyanobacteria can be present. During photosynthesis, carbon dioxide and water molecules are used to make sugar for energy. The members of Phaeophyceae or brown algae are found primarily in marine habitats. Chlorophyll F was recently discovered in some cyanobacteria near Australia 22. FEBS J. This means that it likely functions in a similar way to chlorophyll B to expand the amount of wavelengths of light that can be absorbed for photosynthesis. The other, a green fraction, is a chlorophyll a/c-protein enriched in violaxanthin. Phaeophyta (Brown Algae) - Biology Wise Phaeophyta are greenish-brown colored algae that contain fucoxanthin, beta-carotene and chlorophyll a and c. That means they require carbon dioxide, water, and sunlight (solar energy is collected by chlorophyll A). To do this, cyanobacteria use the pigment chlorophyll a. Between 1,500 and 2,000 species of brown algae are known worldwide. It is demonstrated that the chlorophyll a/c-protein and the chlorophyll a/fucoxanthin-protein complexes are common to the brown algae and diatoms examined, and likely share similar roles in the photosynthetic units of these species. The stipe may be relatively flexible and elastic in species like Macrocystis pyrifera that grow in strong currents, or may be more rigid in species like Postelsia palmaeformis that are exposed to the atmosphere at low tide. In the ocean, light can reach as far as 200m below the surface 25. This sugar is used in the metabolic processes of the organism, and the oxygen, produced as a byproduct, is essential to nearly all other life, underwater and on land 1,24. If a phytoplankton population grows to an excessive amount, the amount of usable oxygen in the water can be depleted 45. So what makes algae only plant-like, instead of plants? Turbidity, or the presence of suspended particles in the water, affects the amount of light that reaches into the water 1. In others (such as Nereocystis), the center of the stipe is hollow and filled with gas that serves to keep that part of the alga buoyant. Phytoplankton require sunlight for photosynthesis. [25] DNA sequence comparison also suggests that the brown algae evolved from the filamentous Phaeothamniophyceae,[26] Xanthophyceae,[27] or the Chrysophyceae[28] between 150[1] and 200 million years ago. An easier and more efficient method is to use a chlorophyll sensor. Like chlorophylls B, C, D, E and F, these molecules improve light energy absorption, but they are not a primary part of photosynthesis. Do red algae and brown algae have chlorophyll? Some species of phytoplankton can suffocate fish during a bloom by clogging or irritating the fishes gills, preventing them from taking in oxygen 53. These cookies will be stored in your browser only with your consent. Regulation of the distribution of excitation energy in Ochromonas danica, an organism containing a chlorophyll-A/C/carotenoid light harvesting antenna. This combination of characteristics is similar to certain modern genera in the order Laminariales (kelps). Like a root system in plants, a holdfast serves to anchor the alga in place on the substrate where it grows, and thus prevents the alga from being carried away by the current. Chlorophyll C can be found in only certain types of algae. This means that chlorophyll is able to absorb all light except for green wavelengths of light. This molecule is used in photosynthesis, as a photoreceptor 20. While large filamentous algal blooms will stop sunlight from penetrating the water and reaching submerged plants, the biggest threat associated with them is oxygen depletion 44. Chlorophyll makes plants and algae appear green because it reflects the green wavelengths found in sunlight, while absorbing all other colors. [5] Some species, such as Ascophyllum nodosum, have become subjects of extensive research in their own right due to their commercial importance. [4] 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. Chlorophyll A is found in all types of organisms that use photosynthesis, which includes both land plants and algae. When on the society site, please use the credentials provided by that society. Red tides and the toxins they release can have a direct or indirect impact on the health of humans and other organisms. 1 What type of chlorophyll is found in brown algae? Chlorophyll A is the primary molecule responsible for photosynthesis 1,15. Due to the presence of this molecule, some organizations will group the green algae into the Plant Kingdom. As phytoplankton populations grow and shrink seasonally, typical concentrations vary not only by location but from month to month 30. It is estimated that 1,800 different brown macroalgae, 6,200 red macroalgae, and 1,800 green macroalgae are found in the marine environment. A personal account can be used to get email alerts, save searches, purchase content, and activate subscriptions. Most freshwater phytoplankton are made up of green algae and cyanobacteria, also known as blue-green algae 13. A red pigment found in red algae and in a few cyanobacteria. Although known as a red tide, the discoloration from a harmful algal bloom is not always red. Chlorophyll A is found in all types of organisms that use photosynthesis, which includes both land plants and algae. While every effort has been made to follow citation style rules, there may be some discrepancies. Although some heterokont relatives of the brown algae lack plastids in their cells, scientists believe this is a result of evolutionary loss of that organelle in those groups rather than independent acquisition by the several photosynthetic members. Chlorophyll sensors are also an in-situ method for determining the trophic state (nutrient-rich, stable, or nutrient-poor) of an aquatic system 47. While phytoplankton can pull carbon dioxide from the atmosphere or the ocean, it will have a similar effect. For example, the most common types of chlorophyll appear as green. They are named due to their colour, which varies from brown to olive green. Do red and brown algae have chlorophyll for Class 8? The largest of the chromists are the Phaeophyta, the brown algae -- the largest brown algae may reach over 30 meters in length. This does not mean that brown algae completely lack specialized structures. Insights into the evolution of extracellular matrix polysaccharides in Eukaryotes", "Chemical and enzymatic fractionation of cell walls from Fucales: Insights into the structure of the extracellular matrix of brown algae", "The new higher level classification of eukaryotes with emphasis on the taxonomy of protists", "The eukaryotic tree of life: Endosymbiosis takes its TOL", "Origin and evolution of organisms as deduced from 5S ribosomal RNS sequences", "Transitions between marine and freshwater environments provide new clues about the origins of multicellular plants and algae", "Brown Algae Carbohydrates: Structures, Pharmaceutical Properties, and Research Challenges", University of California Museum of Paleontology, https://en.wikipedia.org/w/index.php?title=Brown_algae&oldid=1136261539, Articles with dead external links from November 2018, Articles with permanently dead external links, Short description is different from Wikidata, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 29 January 2023, at 14:23. Chlorophyll D is a minor pigment found in some red algae, while the rare Chlorophyll E has been found in yellow-green algae. The cell wall consists of two layers; the inner layer bears the strength, and consists of cellulose; the outer wall layer is mainly algin, and is gummy when wet but becomes hard and brittle when it dries out. Was this answer helpful? Algae can also be classified based on chlorophyll content. Phycoerythrin reflects red light, and can be found in red algae and cyanobacteria. About the Japanese Society of Plant Physiologists, https://doi.org/10.1093/oxfordjournals.pcp.a074631, Subscription prices and ordering for this journal, Purchasing options for books and journals across Oxford Academic, Receive exclusive offers and updates from Oxford Academic. Diatoms, chrysomonads, and brown algae containing chlorophylls a, c1 and c2 in actual proportions. As they need light to photosynthesize, phytoplankton in any environment will float near the top of the water, where sunlight reaches 10. Chlorophyll is found in virtually all photosynthetic organisms, including green plants, cyanobacteria, and algae. Fondriest Environmental, Inc. Algae, Phytoplankton and Chlorophyll. Fundamentals of Environmental Measurements. In addition to Chls c 1, c 2 and c 3, many new Chl c-like pigments have recently been isolated and . On the other hand, phytoplanktonic productivity can be limited by a lack of required reactants such as sunlight. Fertilization may take place in the water with eggs and motile sperm, or within the oogonium itself. Some specific traits that are shared between those in Stramenophile are: (1) chlorophylls a and c and fucoxanthin are the major light-harvesting pigments for photosynthesis and (2 . This polysaccharide is a major component of brown algae, and is not found in land plants. While the overarching kingdom classification is not always agreed upon, the species, genus, family, class and phylum of each alga generally are 6. Species such as Nereocystis luetkeana and Pelagophycus porra bear a single large pneumatocyst between the top of the stipe and the base of the blades. 1989 Aug;21(2):81-91. doi: 10.1007/BF00033362. sharing sensitive information, make sure youre on a federal Certain species of these phytoplankton can contain harmful toxins that can affect humans and other animals. This circulation can cause upwelling (bringing nutrient-rich water to the surface) and instigates phytoplankton transportation. Food reserves are typically complex polysaccharides, sugars and higher alcohols. View your signed in personal account and access account management features. As oxygen is required for fish and other aquatic organisms, a decrease in photosynthesis productivity is detrimental to aquatic populations. While algae contain chlorophyll (like plants), they do not have these specialized structures 8. [50] A large number of Phaeophyceae are intertidal or upper littoral,[26] and they are predominantly cool and cold water organisms that benefit from nutrients in up welling cold water currents and inflows from land; Sargassum being a prominent exception to this generalisation. More often than not, filamentous algae are more of a nuisance than a danger 7. This has lead to their classification under the Kingdom Chromista 4. In most of these organisms, the ratio of chlorophyll A to chlorophyll B is 3:1 21. Like chlorophyll sensors, blue-green algae sensors rely on fluorescence to detect the pigment concentration 49. . KlYOSHI SUGAHARA, NORIO MURATA, ATUSI TAKAMIYA, Fluorescence of chlorophyll in brown algae and diatoms, Plant and Cell Physiology, Volume 12, Issue 3, June 1971, Pages 377385, https://doi.org/10.1093/oxfordjournals.pcp.a074631, At 196C, brown algae and a diatom showed two emission bands of fluorescence at 690695 nm and 705715 nm. This process slowly changed the inert Precambrian atmosphere into the oxygen-rich environment known today 31. Certain species are also used as fertilizer, and several are eaten as a vegetable (e.g., Laminaria) in East Asia and elsewhere. 12.4: Pigments and Evolutionary Adaptations. It does not store any personal data. These cookies track visitors across websites and collect information to provide customized ads. This is in contrast to the occurrence of three low temperature emission bands in green, blue-green and red algae, and in chloroplasts of higher plants. The more nutrients (particularly phosphorus) that are present in a body of water, the more algae and phytoplankton that will grow 7. In the image on the right, a piece of an Ulva thallus is being viewed through a microscope. Plants, algae and cyanobacteria all conduct oxygenic photosynthesis 1,14. [26], Brown algae have a 13C value in the range of 30.0 to 10.5, in contrast with red algae and greens. Marine cyanobacteria have higher levels of phycoerythrin, while freshwater species have dominating amounts of phycocyanin. This cookie is set by GDPR Cookie Consent plugin. [24] Several soft-bodied brown macroalgae, such as Julescraneia, have been found. Chlorophyll sensors rely on fluorescence to estimate phytoplankton levels based on chlorophyll concentrations in a sample of water 47. [41] Likewise, the fossil Protosalvinia was once considered a possible brown alga, but is now thought to be an early land plant. Chlorophyll-bearing organisms lacking true stems, roots, or leaves. The most common cause of this event is lack of oxygen 45. Filter feeders ingest food by taking up the water surrounding them and then filtering out what they do not wish to ingest 52. While they are plant-like in this ability, phytoplankton are not plants. [49] The fertilization of egg cells varies between species of brown algae, and may be isogamous, oogamous, or anisogamous. 1980 May 9;590(3):309-23. doi: 10.1016/0005-2728(80)90202-9. Hence, i n addition to chlorophyll a, brown algae possess Chlorophyll c. Biochim Biophys Acta. diatoms and brown algae) and dinoflagellates. Figure 5.3.3. Chlorophyll c is a form of chlorophyll found in certain marine algae, including the photosynthetic Chromista (e.g. Once a major source of iodine and potash, brown algae are still an important source of algin, a colloidal gel used as a stabilizer in the baking and ice-cream industries. The members of Phaeophyceae or brown algae possess chlorophyll a, chlorophyll c, carotenoids and xanthophyll. A fish kill, also known as a fish die-off is when a large concentration of fish die. Before plants, algae and phytoplankton used water for photosynthesis, bacteria used H2S and other organic compounds to fix CO2 31. This melting process also fuels the oceanic convection, or circulation 38. Phycoerythrin. A food web is a complex net of organisms and food chains (who-eats-who). With less light available, photosynthetic production will decrease. Water temperature will also affect photosynthesis rates 1. 7 Do red and brown algae have chlorophyll for Class 8? [40] A number of Devonian fossils termed fucoids, from their resemblance in outline to species in the genus Fucus, have proven to be inorganic rather than true fossils. Some societies use Oxford Academic personal accounts to provide access to their members. 1980 Jun;1(2):127-35. doi: 10.1007/BF00018229. Light-harvesting systems of brown algae and diatoms. Organisms that use photosynthesis rely on organelles in their cells called chloroplasts. Importance of Algae. Even natural causes can trigger an algal bloom, such as a rainstorm followed by warm, sunny weather 1. Too much heat will denature (break down) the enzymes used during the process, slowing down photosynthesis instead of speeding it up 26. All brown algae contain alginic acid (alginate) in their cell walls, which is extracted commercially and used as an industrial thickening agent in food and for other uses. Furthermore, phytoplankton can be found at multiple depths in the water column, which requires multiple sampling efforts and risks missing layers of phytoplankton in between sample depths 40. He's currently working full-time as a content writer and editor. Cyanobacteria were potentially the first organisms to do oxygenic photosynthesis -- the variety of photosynthesis that produces oxygen as a waste product. government site. diatoms) have chlorophyll a,chlorophyll c, and lipid pigments called fucoxanthins, which together give them a golden-brown color. Cambridge University Press, Cambridge. Copyright 2023 Japanese Society of Plant Physiologists. When the accessory pigments are more concentrated (such as in red algae, brown algae and cyanobacteria), the other colors can be seen 23. As a chemical reaction, photosynthesis is initiated and sped up by heat 26. Whether you need help solving quadratic equations, inspiration for the upcoming science fair or the latest update on a major storm, Sciencing is here to help. The cookie is used to store the user consent for the cookies in the category "Performance". Brown algae- Their pigments are chlorophyll a and c, carotenoids, and yellow-brown pigments. For all phytoplankton, photosynthetic production will increase with the temperature, though each organism has a slightly different optimum temperature range 1. Brown algae multiply by asexual and sexual reproduction; both the motile zoospores and gametes have two unequal flagella. 1980 Dec 3;593(2):427-40. doi: 10.1016/0005-2728(80)90078-x. The spores are then released from the sporangia and grow to form male and female gametophytes.