The categories of marine animals, which can be divided according to taxonomic system or ecology, are presented here separately.
Invertebrates
①Protozoa: the most primitive and simplest animals in the ocean, their main feature is that their bodies are made up of a single cell, so they are also called unicellular animals. However, this single cell of the protozoa is a complete organism, with a variety of functions like those exhibited by higher animals. Such as locomotion, digestion, respiration, excretion, sensing and reproduction. Their distribution throughout the south and north of the sea, the way of life of planktonic, benthic, attached three, of which only the cyprinids camp parasitic life. The largest protozoan is the glow-in-the-dark worm, which is distributed in shallow coastal areas and lives in plankton.
Most of the protozoa are very small and can be observed with the help of a microscope. If you want to observe their organelles, such as cilia, flagella, etc., you need to use an electron microscope.
② sponges: characterized by bone fragments, bone fragments composed of limestone and silica. Adults all live a solid life, attached to rocky reefs, shells, aquatic plants or other objects on the ocean coast and in the water. They can be found all over the world, from the intertidal zone to the deep sea, to freshwater ponds, streams, lakes and rivers.
Sponges are also called porous because of the countless small pores on their body surface. Water flows into the pores in the body, connects with the pipes in the body, and then discharges from the outlet holes. Food and oxygen are brought in through the water flow and waste is expelled. Some sponges can be used for bathing, such as bathing sponges, produced in tropical waters, it is said that there is also the effect of dampness and fitness it!
The regenerative ability of sponges is very strong, if the sponge is cut into small pieces, each piece can live independently, and can continue to grow.
③ Coelenterata: is a primitive multi-cellular animals, including hydrozoa, coral and mantle jellyfish. Hydra generally has two forms of hydra and jellyfish type; coral only hydra type, known as hydrozoa; mantle jellyfish only jellyfish type, such as jellyfish, jellyfish, etc.. Jellyfish form a variety of different sizes, some need to be identified under the microscope, some are large jellyfish, umbrella diameter up to more than one meter, tentacles up to more than 10 meters long, almost like a small parachute.
4 lower worms: including worm, rotifers, nematodes, neuromorphs, with a variety of forms. Some species of nematodes are parasitic and often live in the body cavity of fish; nematodes have long bodies and are mostly benthic marine animals.
⑤Higher worms: including polychaetes, polychaetes and astrocytes. Worms and species of the order Astrocystis. Most are benthic. Polychaetes live in the ocean or semi-saline water; adult worms of astrocystis steel live in the seaside beaches, with muscular body walls and tasty meat, which can be used as food or medicine, killing two birds with one stone.
6 mollusks: all of the brachiopods live in the ocean, widely distributed, in the north and south of China's coastal pipa shell, shaped like bean sprouts, so also known as sea bean sprouts. Shandong coast also produces sour sauce shell. They all belong to the existing species of ancient animals in the ocean, should be considered a living fossil.
Mimetic mollusks also include broom worms, moss animals, almost all of them solid life, with cilia and tentacles will be in the water plankton into the mouth.
⑦Mollusks: These include the Gastropoda, Valvularia and Cephalopoda. The distinctive feature is a soft, unsegmented body with an outer coat membrane and shell, such as abalone, river rays, clams and squid.
Cephalopods are the most specialized of the mollusks, and in many evolutionary respects are the most highly characterized of the invertebrates. They are called cephalopods because of the specialization of the foot into a carpus and funnel, and the carpus and head fused to each other to become the cephalopod.
8 arthropods: in the known more than one million species of animals, arthropods accounted for about 85%, and the number of individuals is very impressive, composed of the main part of the water body plankton, arthropods, the number of uncountable. Arthropods have a high degree of adaptability, so they can be found in any corner of the earth. Perhaps that's why they are so diverse!
Arthropods have body segments and a body divided into head, thorax, and abdomen, and have a chitinous exoskeleton, which is the main raw material for chitin. One of the crustaceans is the more primitive arthropods, in addition to most of the zooplankton, there are shrimp, scale shrimp, pike and so on. Important crustaceans economic animals are shrimps, crabs and a few other species.
The limb stomatopods are the largest species of arthropods in the body, but also the existing species of paleontology. Such as the Chinese horseshoe crab, distributed in the southern coast of China, the body shape is strange, the end of the protruding a long sword-shaped tail-like spines, so it is also known as the sword tail class.
9 Echinodermata: body shape is diverse, star-shaped, spherical, cylindrical or tree-like branches. But basically all belong to the radial symmetry, and to the five-spoke symmetry. The body has spines, and there are calcareous bony lamellar platelets and independent plumbing system in the body wall, living in high salinity water. The so-called five-spoke symmetry means that the body can be cut five different times through the mid-axis of the body from the mouth surface to the anti-mouth surface of the worm, and the two parts cut out are basically symmetrical to each other, such as the sea coaster and the serpent's tail belong to this type. The larvae of echinoderms, however, are symmetrical on both sides. In the whole animal kingdom, only the larvae of echinoderms are bilaterally symmetrical, and the adults are radially symmetrical animals. This cannot be dismissed as a phenomenon of individual developmental degeneration.
There are five orders of extant species of echinoderms, namely, the sea lilies, sea stars, serpentines, sea urchins and sea cucumbers. Among them, the sea lily is the most primitive species, produced in deep-sea waters; sea urchins are warm benthic animals, living in the rocks and coral reefs bottom, widely used in pharmaceuticals. The most economic value of the sea cucumber is the animals of the sea cucumber class, their body structure is very different from other echinoderms, in the shape of a cucumber, it is no wonder that the English word sea cucumber is "sea cucumber" (Seacucumber). Among the 20 kinds of edible sea cucumbers in the world, almost all of them are produced in Xisha Islands of China. The famous edible species of sea cucumber include Spiny Cucumber, Plum Blossom Cucumber, Spoked Anus Cucumber, Snake Eye Bushman's Cucumber, etc. The Spiny Cucumber can be found in the north and south waters of our country. Spiny ginseng is distributed in all seas in the north and south of China.
⑩Hair-jawed animals: the body is slightly transparent, only more than 50 species, but the number is very large, is an important part of the marine zooplankton. Hairy jawed animals, also known as arrow worms, are widely distributed, not only coastal and pelagic distribution, but also warm sea, cold sea and different salinity of the sea are produced.
Protozoa
Protozoa is a general term for the lowest-ranking species of chordates, including those in the subphylum Caudata and Cephalochordata. They are widely distributed and can be found in all parts of the world's oceans. The most common caudal cords are sea squirts, the shape is very similar to a teapot, attached to the sea reefs, seaweeds, shells, etc., the adult body fixed to other things to live.
Cephalopods are a class of non-motorized marine animals, often hidden in the sand, and widely distributed. It can be found almost everywhere, especially in the range between 48° N and 40° S latitudes. The most striking of the cephalopods is the amphioxus, which is found in large numbers in Xiamen, Shantou and Qingdao in China, and can be considered a living fossil. Because of the small mobility of an animal with a large distribution range, it usually takes a long time to pass. Therefore, the amphioxus is often studied as an important object of biological phylogeny. In addition, the amphioxus itself has a high economic value. Although the individual is small, usually 5 to 6 centimeters, the meat is tasty and nutritious, making it a delicious delicacy.
Vertebrates
Vertebrates are the most numerous and evolutionarily advanced group in the phylum Chordata. In the oceans, they carry out separate lifestyles of swimming, floating surfaces, and bottoms, such as fish, reptiles, birds, and mammals. This group of animals is closely related to the material and cultural life of humans. Because the human position in nature is precisely in the vertebrates, so vertebrates for human understanding of their own can also provide a lot of valuable scientific information.
The largest group of marine vertebrates should be fish. China's sea fish as many as 2,000 species, of which the economic value of more than 200 species. The largest vertebrates caught in the ocean are fish.
Fish often have a kind of periodic, directional and group migratory activities in their life activities - migration. Migration is an adaptation of fish to their environment. By virtue of this activity, fish can meet the environmental conditions required at a certain period of life, so that the survival and reproduction of the population is ensured.
There are three main ways in which fish migrate, namely, reproductive migration, baiting migration and overwintering migration. At a certain time and place, fish schools appear in large numbers, the formation of fishing grounds and fishing season. It can be said that most of the fishes belong to migratory fishes, only that the migration activities of some fishes are not very significant. A few fish, such as sea dragons, river flounder, etc., do not show migratory phenomena, called sedentary fish.