An autotrophic organism that uses chlorophyll for photosynthesis to produce organic matter in the ocean. From lower eukaryotic algae to higher seed plants, there are many kinds, including *** 13 phylum and 10000 species. Among them, diatoms are the most, reaching 6000 species; Prochlorophyta is the least, only 1 species. Marine plants are mainly algae. Seaweed is a simple photosynthetic organism with complex morphological structure, lifestyle and evolution process, which is between photosynthetic bacteria and vascular plants and plays an important role in the origin and evolution of organisms. There are not many species of marine seed plants, and only 130 species are known, all of which belong to angiosperms. It can be divided into mangrove plants and seaweed. Together with other creatures, they form a biological community along the coast of the ocean.

Seaweed is the main body of marine plants and a great natural wealth of human beings. At present, there are more than 100 kinds of algae that can be used as food. Scientists divide algae into planktonic algae and benthic algae according to their living habits.

Cyanobacteria, diatoms, dinoflagellates, Chrysophytes and some unicellular green algae, many of which are feeds for marine animals such as crustaceans, shellfish, sea cucumbers, barracuda, anchovies and whales, play an important role in the reproduction of marine animals. There are more than 200 species of cyanobacteria in China's coastal areas, which are gelatinous, blue-green or dark green and sticky. There are about 500 species of red algae, most of which are red, crimson or purplish red, which have great economic value and rich resources. About 250 species are common in coastal areas of China. Some varieties have been cultivated artificially, such as kohlrabi, laver and eucheuma. , are popular food; Gelidium, Qiongzhi, hedge, carrageenan, etc. It is the raw material of medicine and food industry such as agar and carrageenan. Sedum japonicum, Swertia japonica and seaweed are the main raw materials of pharmaceutical industry, with calcium carbonate coating on the surface and coral appearance. There are about 300 species of brown algae, among which about 150 species are common, which have great economic value and rich resources in coastal areas of China. At present, cultured kelp, Undaria pinnatifida and Sargassum fusiforme are the main industrial raw materials of alginate, mannitol, iodine and calcium chloride, and they are also popular foods. This brown algae mainly grows in the Yellow Sea, Bohai Sea and East China Sea. Sargassum is a kind of brown algae with abundant natural resources, the most species and great economic value, which is mainly produced in the South China Sea of China.

In the history of the Irish people, there are also records of relying on red algae and green algae to spend the famine year. The habit of eating seaweed in western countries is not as common as that in eastern countries. An oceanographer from western countries once lamented that eating seaweed in China and Japan is as common as eating tomatoes in the United States and Britain. He hopes that one day, westerners will develop the habit of eating seaweed like orientals.

There are few species of marine seed plants, which mainly grow in rocky swamps in low tide zone or rocks in subtidal zone. Common kelp, red fibrous root shrimp algae, salt marsh vegetables, etc., are important economic types, mainly used in paper making and building materials industries.

marine animal

marine animal

Heterotrophs in the ocean. There are many categories, and the morphological structure and physiological characteristics of each category can be very different. They feed on organic turtles and their remains of plants, microorganisms and other animals. It is estimated that there are1.6 ~ 200,000 species, ranging from unicellular protozoa to blue whales with a body length of more than 30 meters and a weight of 1.90 tons. From the ocean to the seabed, from the coast or intertidal zone to the bottom of the deepest trench, there are marine animals in the water and above the global ocean.

Marine animals can be divided into three categories: marine invertebrates, marine protozoa and marine vertebrates: ① marine invertebrates. It accounts for the vast majority of marine animals and has the largest variety. The main animals are protozoa, sponges, coelenterates, flatworms, molluscs, linear animals, annelids, molluscs, arthropods, brachiopods, echinoderms and echinoderms. ② Marine protozoa. Animals between vertebrates and invertebrates in the ocean. Including urochordates and cephalochordates. ③ Marine vertebrates. Including fish, reptiles, birds and mammals that depend on the sea.

Animals distributed in the ocean. The living conditions of the ocean are relatively consistent and the area is vast. Besides fish and whales, there are zooplankton and swimming animals, such as cephalopods and jellyfish. In the deep sea, only animals that do not depend on plankton are found.

In many marine areas, ocean currents bring nutrient-rich deep seawater to the shallow layer, increasing the fish production in the shallow layer of the ocean. Benthic animals living on the seabed include fixed animals, such as sponges, coelenterates and nereis, and mobile animals, such as crustaceans, mussels, annelids and echinoderms.

Coral animals are most developed in tropical oceans. Coral reefs are deposited by a large number of chalky skeletal materials of reef-building animals and plants (especially corals and bryozoa). The coral reef environment has the densest animals and the most species.