The department Red algae ("criminals") includes about four thousand species and more than six hundred genera. The oldest representatives found in the Cambrian deposits age about 550 million years.
В связи с наличием ряда особенностей, красные algae are considered a separate sub-kingdom in the plant kingdom. In chromatophores of parasites, in addition to chlorophylls and carotenoids, some water-soluble pigments, phycobilins, are present. As a reserve polysaccharide is a crimson starch. Its grains are deposited outside the chloroplasts in the cytoplasm.
Gametes and spores of purples do not have flagella.The cycle of their development includes three stages. From a zygote (after a confluence) a diploid organism is formed - a sporophyte. It produces diploid disputes, from which the second generation is formed. In the cells of the new sporophyte, a certain period of meiosis occurs and haploid spores develop. Of these, a third generation is being formed - the gamete-producing haploid gametophyte producing gametes.
In the composition of cellular membranes of red algaehemicelluloses and pectins are present. They have the ability to swell strongly, merging into the total mass of mucus. Often, the threads of the thallus (shoot) are glued together with mucous substances and become slippery to the touch. In the intercellular spaces and cell walls of many red algae, there are phycocolloids. These sulfur-containing polysaccharides are widely used in human economic activity. The most popular are agaroid, carrageenin and agar. Many red algae are distinguished by the presence of calcium carbonate in the walls of cells. This component gives crimson rigidity.
A large number of red algaethe formation of thalli is carried out by means of interwoven multicellular filaments. They attach to the substrate with the help of rhizoids. The size of the thallus ranges from a few centimeters to a whole meter.
Red algae predominantly inhabit the seas. There criminals always attach themselves to shells, stones and other objects on the bottom. Sometimes algae can be found at a sufficiently deep depth.
Callitamnion corymboid - typical redalgae. This crimson representative forms very elegant bushes up to ten centimeters high, bright pink in color. These bushes consist of considerably branched filaments.
Nemalion - another representative of red algae - grows on sea rocks. Its pale pink cords reach five millimeters in thickness and twenty-five centimeters in length.
In algae of the genus Delesseria, bright red thalli resemble leaves.
In the warm seas are widespread scarletCoraline. Their thalli are composed of segments impregnated with lime and joined by joints (with a low content of lime). This gives flexibility to the plant, which helps to withstand the effects of waves and develop in areas of strong surf.
Crimson are widely used by man in economic activity. As you know, these algae are a very valuable product due to the presence of protein, trace elements, vitamins.
In the Hawaiian Islands, in the East Asiancountries from purple prepared a variety of dishes. Use these algae in a candied or dried form. From edible crimson, porphyry and rhodium are popular. These algae are found in many seas. In Japan, industrial cultivation of these plants is quite widespread. In the coastal strip, rocks, branches or stretches are laid in shallow water, woven from thick ropes and fastened on poles made of bamboo. After a certain period of time, all these objects acquire algae.
