Protists — The phylloscopus dinoflora
Haptophyta ( scientific name : Haptophyta ) is a class of eukaryotes belonging to the polymorphic organism Diphtheria , which was once classified in the vesicular algae world. In 1955, Parke et al. introduced "Haptonema" to describe the third flagella at the tip of the cell. Its main feature is also the cell surface wrapped in scales.
The phylum Dinoflagellates is predominantly single-celled algae. Most species have a filamentous structure called attached flagella between their two fluctuating feet. It is speculated that this structure is used as a temporary anchor, possibly curled up as cells move. Dinoflagellates are commonly found in marine and freshwater plankton.
Evolutionary clades of cryptophylum Cryptophyta Cryptophylum Cryptoalgae Clematis CryptophytaAlveolata.
From the fish pond of a large number of dead fish, the strain of Prymnesiumporvum was collected and isolated, and a single culture was successfully carried out in the laboratory, when the temperature was 23 °C, the light was 600-800 lx salinity of about 12-16 ‰, the algae grew well in seawater and artificial seawater medium, and the hemolytic toxin activity was the highest in the log growth stage to the equilibrium stage.
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Dinoflagellates are mainly single-celled algae. Most species have a filamentous structure called attached flagella between their two fluctuating feet. Typically, in the front end of the swimming cell, in addition to having two tail whips of equal length, there are also attached flagella. The adjuncted flagella is thinner than normal compound flagella and consists of a three-layer membrane around it and 6-7 small fibers that walk longitudinally inside. It is speculated that this structure is used as a temporary anchor, possibly curled up as cells move. On the surface of swimming cells, secretions of scaly objects are attached, and the main component of the secretions is calcium carbonate, which is different from the silicic acid secreted by the golden algae.
The main genera of the order dinoflagellates are isoflagellus, membranosporus and calcareous plate algae.
Dinoflagellates are commonly found in marine and freshwater plankton. It is an ocean planktonic algae with a wide range of temperature and salinity adaptations.
Dinoflagellates are widely distributed, occurring in marine ecosystems from the polar to temperate regions.
Dinoflagellates are an important part of marine primary productivity, containing many species that can form large-scale algal blooms and important economic bait species, which play an important role in the ecological environment and aquaculture.
In addition, dinoflagellates play an extremely important role in the biogeochemical cycle of carbon and sulfur (especially in polar and coastal areas), the structure of the food web, and global climate change. Under eutrophic conditions, Dinoflagellates form harmful red tides in the form of groups, inhibit the development of other phytoplankton communities and zooplankton feeding, and produce hemolytic toxins, dimethyl sulfides and thiouric acid and other toxic marine organisms; after the algal blooms subside, a large number of white foams are generated to float on the water surface, endangering the water ecosystem and affecting the coastal landscape.
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Single-celled algae refer to embryoless, autotrophic, low-grade plants that reproduce in spores. Algae are single-celled, population or multicellular bodies, which must be seen by microscopy, and large ones such as Sargassum and giant algae can be up to several meters, tens of meters to hundreds of meters. The internal structure begins to differentiate on the cell without true roots, stems, and leaves. The whole algae body is a simple leaf body containing chlorophyll for photosynthesis. The reproduction of algae is basically the germination into new individuals by single-celled spores or zygotes leaving the mother directly or after a short period of dormancy.
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Algae have an extremely wide range of distribution, are not strict on environmental conditions, are highly adaptable, and can live at only very low nutrient concentrations, very weak light intensities and fairly low temperatures. It can grow not only in rivers, streams, lakes and oceans, but also in places where water is short or wet. From the tropics to the poles, from snowy mountains to warm springs, from wet ground to not very deep soil, algae are distributed almost everywhere. There are marine species in all the algae outside the gate except for the rotifer.
According to different ecological habits, algae can be divided into planktonic algae and benthic algae. Planktonic algae are small algae that float in the water, including diatoms, dinoflagellates, golden algae, yellow algae, cryptoalgae, naked algae and cyanobacteria, as well as single-celled species of the phylum green algae. Other species of the Phylum Chlorella, especially the phylum Brown Algae and the Phylum Red Algae, are all large multicellular marine benthic algae. Benthic algae, like terrestrial plants, require a fixed growth base. It is generally distributed on the substrate along the coast, in the intertidal zone or in shallow water. According to the growth area, algae can be divided into freshwater algae, seaweed, brine algae, flowing water algae, aerophytic algae, soil algae, hot spring algae, ice and snow algae and epiphytic algae.
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Temperature is a major factor affecting the geographical distribution of algae. Seaweed can be divided into 3 types according to the difference in temperature of the place of growth:
(1) Cold-water species. The optimal temperature for growth and reproduction is less than 4 °C, and it can be divided into cold zone species with a suitable temperature of about 0 °C and subarctic species with a suitable temperature of 0 to 4 °C.
(2) Warm water species. The optimal temperature for growth and reproduction is 4 to 20 °C, which can be divided into cold temperate zone species with a suitable temperature of 4 to 12 °C and warm temperate zone species with a suitable temperature of 12 to 20 °C.
(3) Warm water species. The growth and reproduction temperature is greater than 20 °C, and can be divided into subtropical species with a suitable temperature of 20 to 25 °C and tropical species with a suitable temperature greater than 25 °C.
Most seaweeds are not adaptable to temperature, so in the sea areas where sea temperature changes greatly, the species varies greatly throughout the year, with cold-water algae in winter and warm-water algae in summer, which can complete the life cycle in a relatively short temperature time. However, some benthic seaweeds are highly adaptable to temperature changes, such as the lettuce, which can grow almost all over the world throughout the year. Most of the diatoms and golden algae in freshwater algae appear in spring and autumn and belong to the narrow cold species; some cyanobacteria and green algae appear only in the summer when the water temperature is high, and are narrow temperate species.
Light is the decisive factor in determining the vertical distribution of algae. The absorption capacity of water bodies to light is very strong, the light intensity at a depth of 10 meters in a lake is only 10% of the surface of the water, and the light intensity at a depth of 100 meters in the ocean is only 1% of the surface of the water; and because seawater is easy to absorb long-wave light, it also causes spectral differences between water layers. Various algae have different requirements for light intensity and spectrum, green algae generally live in the surface layer of water, while red algae and brown algae can use short-wave light such as green, yellow and orange to live in deep water.
The chemical properties of water bodies are also important factors in the emergence of algae and their species composition. For example, cyanobacteria and naked algae are easy to appear in large quantities in nutrient-rich water bodies and often form blooms; diatoms and golden algae are often found in large quantities in nutrient-poor lakes in mountainous areas; chlorella and cryptoalgae often appear in large quantities in small ponds.
In addition, the interaction of algae living in the same waters also plays an important role in their emergence and prosperity, and some algae can secrete substances to inhibit the formation and development of other algae.
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The economic importance of algae is mainly manifested in:
(1) Algae use photosynthesis to fix inorganic carbon and convert it into carbohydrates, thereby providing a basis for water productivity. The total productivity of marine plankton algae is estimated at 31×10 littoral tons of carbon per year. In the transformation of the food chain, about 100 to 1000 kg of phytoplankton algae is needed for 1 kg of fish meat, so the sea areas rich in phytoplankton algae resources are the locations of world-famous fisheries, and the production of phytoplankton algae is an indicator of marine productivity.
(2) In pond fish farming, the water quality is generally judged according to the water color, and the water color is determined by the dominant species of algae and their degree of reproduction. For example, when the blood red-eyed insect algae is dominant, it shows red blooms, indicating that the water quality is poor and thin; when chlamydia is dominant, it is dark green blooms and sticky blisters, indicating that the water quality is fertile; the pond water is patina-colored yarn flocculent bloom when microcystis and fibrillary algae and fishy algae are dominant; the blue bloom formed by the blue naked algae is one of the typical water quality of the high-yield fish ponds of farmed silver carp, bighead carp, carp, crucian carp and non-crucian carp, but excessive reproduction will also worsen the water quality and cause fish ponds. In addition, single-celled algae such as flat algae, dubella, chlorella and other single-celled algae have high protein content and are important natural food for shellfish, shrimp and sea cucumber farming.
(3) Nitrogen-fixing cyanobacteria are important organisms on earth that provide compounded nitrogen, and are also important biological nitrogen fertilizer resources that can be used. There are more than 120 species of nitrogen-fixing cyanobacteria known, and the amount of nitrogen fixed in rice fields per hectare reaches 16 to 89 kg.
(4) Kelp and wakame of the brown algae gate, nori of the red algae gate, hair vegetables of the cyanobacteria gate, and lettuce and moss of the green algae gate are all important edible algae.
(5) The industrial use of algae is mainly to provide various algal gums. Kelp, kelp, wakame, carob, sheepseed, etc. of the brown algae gate can be used as raw materials for iodine, mannitol and fucoidan in addition to food. Macroalgae, bulbous algae and other sargassum can also be used as raw materials for extracting fucoidan. Fucoidan is widely used in the food, paper, chemical and textile industries. From stone cauliflower, river lily, fairy vegetables, etc., agar gum can be extracted as a raw material for the pharmaceutical and chemical industries and as a culture agent for microbiological research. Carragee, which is widely used in the food industry, can be extracted from algae such as hornbill algae, unicorn, fir algae, sand vegetables, ginkgo biloba, forked algae, centipede algae, sea lotus and Igu grass.
In addition, algae can also be used for sewage purification and as indicator organisms for measuring ocean currents, and also play an important role in transforming abiotic areas of nature into areas suitable for biological growth.
The methods by which algae reproduce are diverse and very complex. A brown algae that grows on rocks, the ink horn algae, is a typical example. Algae can be male or female, or both male and female. At a certain time, the edges of the phylloids appear to expand, enveloping the reproductive organs used to produce reproductive cells (or gametes), and the produced reproductive cells are released into water and fertilized in the water, that is, the male gametes and female gametes fuse to form a single cell- a fertilized egg, which is then grown into a new plant.
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