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

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

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, which can be used to sense 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.

When the leopard frog climbs from the bottom of the sea and swims in the water, the pectoral fin and the three independent fins in front of the fin gather together and cling to the side to reduce the resistance in the water. When the leopard's swimming reaches its climax, it rushes out of the water at a very fast speed, then spreads its "wings"-pectoral fins, and flies in the air. In fact, the "flying" of the leopard and the "flying" of the flying fish are not really flapping their wings, just relying on the role of the 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 become dry and stick together, which hinders breathing and stops life. However, there is a kind of mudskipper that can adapt to the amphibious life along the coast of China.

The body length of the mudskipper is about 10 cm, slightly backward, with eyes above the head, like frog eyes, and a wide field of vision. Its gill cavity is very 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 tail 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 and prefer to climb to the roots of mangroves to catch insects. Therefore, people call it a "tree-climbing fish".

A fish that can make a sound.

Most people think that fish are dumb, which is obviously wrong. Many fish make all kinds of amazing sounds. For example, Ji Kang carp will make a "woof" sound; The electric catfish sounds like a cat's anger; Box bream can make dogs bark; The sound of gills is sometimes like a pig's cry, sometimes like a groan, sometimes like a snore; The hippocampus will make a monotonous sound like a drum. Rock fish is famous for its beautiful sounds, such as rolling, drumming, hummingbirds flying, cats meowing and whistling. Their calls are particularly common in breeding and are aimed 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 anemone

Neither benefit nor suffer, this phenomenon is called symbiosis. In the coral reefs of the South China Sea and the tropical oceans of the world, there is a small fish with bright red and white ribbons on its body, which is clear and beautiful and very eye-catching. This kind of small fish is called double saw fish, commonly known as clown fish.

Double sawfish often live with anemones, which is a typical example of marine animals living in groups.

In general, any animal that comes into contact with an anemone will be anesthetized or killed by the stingers in the stinging cells on the petal-shaped tentacles of the anemone. But the double saw fish is an exception. They can not only move around anemones, but also move back and forth between anemones' tentacles unscrupulously. Bright-colored double sawfish will cause many fierce carnivorous fish to chase. At this time, the double saw fish fled to hide between the tentacles of the anemone to avoid being preyed by the enemy. However, the fierce fish close to the anemone tentacles were anesthetized to death by the stings from the anemone tentacles, which became a delicious meal for anemones.

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

If people take anemones, sawfish will be eaten by other fish. Anemones protect sawfish, which bring food and enough oxygen to anemones. This is nature's unique arrangement for mutually beneficial partners.

Cephalopods-animals whose feet are born in the head

Cephalopod is a general term for many kinds of animals, including more than 400 kinds of mollusks existing in the world, such as squid, soft fish, octopus, octopus, nautilus and so on. Cephalopods, as the name suggests, are a group of mollusks that live in 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 maintains the appearance of ancient ancestors, so it is recorded as a "living fossil" in the history of zoology.

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

Nautilus crawls in shallow water about 100 meters, while octopus lurks in underwater caves, crevices or stones. You can use the natural "eight feet" on your head to tightly wrap shrimps and crabs with hard shells and then eat them. Squid and soft fish swim quickly by using the recoil obtained from the abdominal "funnel" by spraying water, so they are called "underwater rockets". They swim fast to catch food and escape from the enemy. The king squid living in the deep sea is 18 meters long and weighs about 30 tons. One of its "legs" is 25 cm in diameter and as thick as a telephone pole. There are hundreds of suckers on its "legs", and the largest sucker is as big as a dish.

The king squid is not only the "eldest" among cephalopods, but also the largest among 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, which can glow at the bottom of the sea. Its length is only 5 cm. Squid is very 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. 1 g, and has a sucker on its back. The micro-fin squid uses the sucker to absorb its body on seaweed to rest. This octopus is not only unique in appearance, but also unique in that its female and male individuals are very different. Male individuals are very small, and attaching to women's bodies often leads people to mistake them for parasites parasitic on women's bodies.

Rich and 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 value plants.

Algae vary greatly in size. The smallest marine unicellular algae is very small and 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 kinds of seed plants in the ocean, such as kelp and mangroves.

Marine plants are the "fertile grasslands" of the marine world. They are not only the natural "pasture" of marine fish, shrimp, crab, shellfish, marine animals and other animals, but also the green food for human beings, the supplier of widely used industrial raw materials and agricultural fertilizers, 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 nutrients of marine plants.

Seaweed is a big family of marine life. There are more than 8,000 species of unicellular diatoms and dinoflagellates, up to several hundred meters. Brown algae is a unique algae position in the ocean, which is characterized by its huge volume. Macroalgae, fuciformes, cysticercus, kelp and Sargassum are famous brown algae. Kelp is a favorite seafood in China. It is not only rich in seafood, but also nutritious, containing minerals and vitamins such as iodine, which 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. Historically, British sailors used red algae to prevent scurvy; 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.

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

Algae are lower autotrophic plants containing chlorophyll and other accessory pigments. 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 is also called thallus.

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.