Climbing, swimming and flying triathlon fish, a leopard and a scorpion.

Fish can't live without water. This sentence shows that fish spend their whole lives in water, so swimming in water is the instinct of fish. But some fish can swim in the water, but also "fly" in the air, such as flying fish; Some can jump on the beach, such as mudfish. These fish can "fly" and jump. They only have two skills. However, the leopard crab has three skills of crawling, swimming and flying, and it can be said that it has the ability of three-dimensional movement of "sea, land and air".

The three fins of the pectoral fin of the leopard crab are independent and can move freely. With these three fins, it can crawl freely on the vast seabed. At the same time, these independent fins are also the tactile organs of the leopard, and they can be used to perceive the surrounding environment of the seabed. Because of the special functions of these three independent fins, the muscles that drive these fins are particularly developed. This is the result of natural selection and natural selection.

When the leopard frog crawls from the bottom of the sea to swim in the water, the pectoral fin and the three independent fins in front of the fin are gathered together and cling to the side to reduce the resistance in the water. When the leopard's swimming reached its climax, it rushed out of the water at a very fast speed, and then spread its "wings"-pectoral fins, flying in the air. In fact, the "flying" of the leopard and the "flying" of the flying fish are not really flapping wings, but only rely on the role of wind.

Fish that can climb trees

The main respiratory organ of fish living in water is gill. When the fish leaves the water, the gills are dry and stick to each other, preventing breathing, and life stops. However, there is a kind of mudskipper that can adapt to amphibious life along the coast of China.

The body length of the mudskipper is about 10 cm, slightly behind, and its eyes are above the head, like frog eyes, with a wide field of vision. Its gill cavity is large and its gill cover is sealed, which can store a lot of air. The epidermis in the cavity is covered with vascular network and plays a role in breathing. Its skin is also covered with blood vessels, and blood can directly exchange gas with air through extremely thin skin. Its caudal fin is not only a fin in water, but also an auxiliary respiratory organ. These unique physiological phenomena enable them to live in the air for a long time without water. In addition, the left and right ventral fins of the mudskipper are combined into a sucker shape, which can be adsorbed on other objects. The developed pectoral fin is arm-shaped, much like the appendage of higher animals. When it is attacked by the enemy, it moves faster than people walk. In order to catch food at low tide, mudskippers living in tropical areas often jump around on the beach, preferring to climb to the roots of mangroves to catch insects. Therefore, people call it "the fish that can climb trees".

A fish that can make sound.

Most people think that fish are all dumb, which is obviously wrong. Many fish make all kinds of amazing sounds. For example, Kangji carp will make a "bark" sound; The sound of electric catfish is like a cat's anger; Box bream can make dog barks; The sound of the gills is sometimes like a pig's cry, sometimes like a groan, and sometimes like a snore; The hippocampus will make a monotonous sound like a drum. Stonehead fish are famous for their good calls, such as rolling, drumming, flying of hummingbirds, meowing of cats and whistling. Their calls are particularly common during reproduction, aiming at clustering.

Most of the sounds made by fish are caused by bone friction and contraction of swim bladder, and some are made by breathing or anal exhaust. Experienced fishermen can judge the number of fish according to the sound they make, so as to catch fish in the net.

Double sawfish and sea anemone

Neither benefit nor suffer, this phenomenon is called * * * habitat. Among the coral reefs in the South China Sea and the tropical oceans of the world, there is a kind of small fish with bright red and snow-white ribbons on their body surfaces, which are clear and beautiful and very eye-catching. This kind of small fish is called double saw fish, and its common name is clown fish.

Double sawfish often live with sea anemones, which is a typical example of marine animals' habitat.

Under normal circumstances, as long as any animal touches the anemone, it will be anesthetized or killed by the poisonous stings in the stinging cells on the petal-shaped tentacles of the anemone. But the double sawfish is an exception. They can not only move around the sea anemone, but also travel back and forth between the tentacles of the sea anemone unscrupulously. Double sawfish with bright colors will cause many fierce carnivorous fish to chase. At this time, the double saw fish fled to hide between the tentacles of the sea anemone to avoid being preyed by the enemy. However, the fierce fish close to the tentacles of the sea anemone were anesthetized to death by the stinging silk from the stinging cells of the tentacles of the sea anemone, which became a delicious meal of the sea anemone.

On the other hand, because the double sawfish move around the anemone and between the tentacles, the flow of water around the anemone is strengthened, so that the anemone can get enough oxygen.

If people take away the sea anemone, the sawfish will be eaten by other fish. The sea anemone protects the sawfish, and the sawfish brings food and enough oxygen to the sea anemone. This is a unique arrangement of nature for mutually beneficial partners.

Cephalopods-animals whose feet are born in the head

Cephalopod is a comprehensive term for many animals, including more than 400 kinds of mollusks existing in the world, such as squid, soft fish, octopus, octopus and nautilus. Cephalopods, as the name suggests, are a group of mollusks that live on the head.

Nautilus is the oldest cephalopod in existence, and the ancient ocean was once its world. In the long evolution process of hundreds of millions of years, Nautilus is very conservative, and still keeps the appearance of its ancient ancestors, so it has been recorded in the history of zoology as a "living fossil".

Cephalopods are widely distributed in the world's oceans, ranging from shallow sea to 3500 meters deep sea, surface layer, middle layer, bottom layer and even seabed, and they are found everywhere in cold zone, tropical zone and temperate zone oceans.

Nautilus crawls in the shallow water about 100 meters, while octopus lurks in underwater caves, rock crevices or stones, and can use the "eight feet" born on the head to tightly wrap shrimps and crabs with hard shells and then eat them. Squid and soft fish can swim quickly by using the recoil force obtained from the "funnel" in the abdomen by spraying water, so they are called "underwater rockets". They swim fast to catch food and escape from enemies. The king squid, which lives in the deep sea, has a body length of18m and weighs about 30 tons. One of its "legs" is 25 cm in diameter, as thick as a telephone pole. There are hundreds of suckers on its "legs", and the biggest sucker is as big as a dish.

The king squid is not only the "eldest" of cephalopods, but also the largest of all invertebrates. It dares to fight to the death with the largest toothed whale-sperm whale!

The "dwarf" in the squid family is a fluorescent squid that can glow at the bottom of the sea. Its length is only 5 cm. Squid is small. But not the youngest member of this family. The smallest squid is the micro-fin squid, which is only 1.5 cm, as big as a small peanut, and weighs only 0.l grams. It has a sucker on its back, and the micro-fin squid uses the sucker to absorb its body on seaweed to rest. The octopus is not only strange in shape, but also strange in that its female and male individuals are very different. The male individual is very small, and attaching to the female body often makes people mistakenly think that it is a parasite on the female body.

Colorful marine plants

In the vast and rich ocean, there are many kinds of marine plants besides all kinds of animals. Marine plants can be simply divided into two categories: lower algae plants and higher seed values.

The size of algae is very different. The smallest marine unicellular algae is so small that it can only be seen under a microscope, while the largest giant algae can reach 200-300 meters long, which is the highest among algae. There are few species of seed plants in the ocean, such as kelp and mangrove.

Marine plants are the "fertile grassland" of the marine world. They are not only the natural "pasture" of marine fish, shrimp, crabs, shellfish, sea animals and other animals, but also the green food for human beings, the supplier of industrial raw materials and agricultural fertilizers with wide uses, and the important raw materials for manufacturing marine drugs. Some algae, such as giant algae, can also be used as energy substitutes. Light is the energy of marine plants, temperature is the growth factor of marine plants, and mineral nutrients are the nutrients of marine plants.

Seaweed is a big family of marine life. There are more than 8,000 kinds of single-celled diatoms and dinoflagellates, up to several hundred meters high. Brown algae is a unique algae position in the ocean, which is characterized by its huge size. Macroalgae, Fucoid, Cysticercus, Kelp and Sargassum are among the famous brown algae. Kelp is a seafood that Chinese people like to eat. It is not only full of seafood, but also rich in nutrition, containing iodine and other minerals and vitamins, and can prevent and treat thyroid diseases (commonly known as big neck). Seaweeds with edible and medicinal value include laver, Undaria pinnatifida, and cauliflower, which are very familiar to our people. People in eastern countries such as China and Japan have a long history of eating seaweed and using it as medicine. In history, British sailors used red algae to prevent and treat scurvy; In the history of the Irish people, there have also been 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 a western country 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, West Renye Fang will develop the habit of eating seaweed like the orientals.

Algae is an ancient and primitive low equivalent, which is widely distributed in rivers, lakes and oceans. It is a large group of plants with many kinds and forms.

Algae are low autotrophic plants containing chlorophyll and other accessory pigments, and the plants are single-celled, single-celled or multicellular. Algae has no real difference between roots, stems and leaves, and the whole plant is a simple thallus. All parts of algae have the function of making organic matter, so algae are also called phyllosomes.

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 marine algae that can be used as food. Scientists divide algae into planktonic algae and benthic algae according to their living habits.