What are the characteristics of the external morphological structure of the fish that are compatible

The streamlined shape is suitable for swimming in the water.

Some fish have whiskers near their mouths, such as two pairs of carp and catfish, and four pairs of bearded catfish in Egypt. It must have a sensory and gustatory effect in water, and can assist in food hunting.

There is a nasal cavity on the left and right sides of the front and upper part of the fish eye, which is separated by membranes and is divided into two nostrils, the latter is not connected with the oral cavity, so the nostrils of the fish have no respiration function, only olfactory function.

There is a pair of gill holes on the posterior edge of the operculum on both sides of the posterior part of the head (only eels, which are special for eels and have one left and right gill holes, located on the ventral surface), which is a passage out of the water when breathing.

The trunk and tail of fish mainly have fins, scales, and lateral line organs. Fin is the locomotor organ of fish, which can be divided into dorsal fin, pectoral fin, pelvic fin, anal fin and caudal fin according to the position of its birth. When a fish swims in the water, its fins work together to keep its body balanced and act as a propulsion, brake, or turn.

Most fish have solid scales on their body surface, which are derivatives of ** and are usually arranged in a shingle-like pattern. Some fish (eels and eels) have degraded scales, while others have few scales remaining, such as mirror carp. Regardless of the scale or lack of scales, the body surface of the fish can secrete a large amount of mucus, which undoubtedly has the effect of lubricating and protecting the fish body in the water.

The lateral line is a sensory organ unique to fish. It is a tubular system deep under the skin and is closely connected to the nervous system. There are many small tubules that pass through the scales to communicate with the outside world.

These pores are arranged in a line on the lateral surface of the body. Common freshwater fish have only one lateral line, which runs roughly from the back of the head along the midline of the body to the base of the caudal fin. However, the lateral line of the Nile crucian carp is interrupted and divided into upper and lower segments.

The lateral line has auditory and tactile functions and can sense the vibrational waves of water, the direction of water flow, and changes in water pressure.

All characteristics are yes:

1. Body type: shuttle type, streamlined shape, which is conducive to reducing the resistance in the water and facilitating activities.

Second, the mucous membrane and fish scales on the body surface: reduce resistance.

Third, by respirating with gills, oxygen can be taken in water (an environment with a low partial pressure of oxygen).

Fourth, fish bladder. You can adjust the ups and downs of the body in the water in this defibrillation joint.

5. Fins: Strong fins and corresponding muscle groups allow it to move freely in the water, including forward, backward, and maintaining balance.

Sixth, the lateral line of the body: a receptor that can detect the depth of water.

7. The urinary system of fish.

Regulates its own water-salt balance in water. Adapt yourself to the environment of fresh water or seawater, so as not to cause dehydration or salt poisoning in the body of the bridge.

Eighth, the circulatory system.

Single circulation, which is convenient for the delivery of nutrients and oxygen to various tissues of the body.

There are also features such as the skeletal system.

I recommend you to take a look at Mori, Animal Biology, there is a more systematic introduction above, and I remember these.

Fish body shape: The body shape of the fish is fusiform, which is beneficial for reducing resistance when swimming. Body color of the fish:

Because the body surface of the fish is covered with scales and there is mucus on it. Scales and mucus have a protective effect on the fish's body, and mucus reduces resistance when swimming.

Lateral line of the fish: There are two lines on both sides of the fish, which consist of small holes in the scales. These two lines are the lateral lines of the fish, which are connected to the nerves and have the function of determining the direction and sensing the current.

Locomotor organs are used for paddling.

Fishes are ectothermic aquatic vertebrates that swim and feed with their upper and lower jaws by respiring with their gills, swinging their tails and trunks, and feeding on their upper and lower jaws, and belong to the vertebrate subphylum of chordates, and generally divide vertebrates into five categories: fish (53%), birds (18%), reptiles (12%), mammals (9%), and amphibians (8%).

According to the statistics of the late Canadian scholar Nelson in 1994, there are 24,618 species of fish in the world, accounting for more than half of the named vertebrates, and new species of fish are constantly being discovered, with an average of about 150 species per year, and more than 1,500 species should have increased in more than ten years, and the number of named fish species in the world is about 32,100 species.

Animal characteristics. 鲬字 pinyin (yú), fish (fish) is the oldest vertebrate. They inhabit almost every aquatic environment on Earth – freshwater lakes, rivers to saltwater seas and oceans.

There are about 32,000 species of fish found in the world, and the fish live in the water, distributed in the ocean and freshwater, with two-thirds of the fish living in the ocean and the rest living in freshwater. There are 2,500 species in China, of which there are more than 100 kinds that can be used for medicinal purposes, and the common medicinal animals are seahorses, sea dragons, yellow eels, carp, crucian carp, sturgeon (swim bladder is fish maw gum), large yellow croaker (otolith is fish brain stone), liver oil (vitamin A and vitamin D) are the main raw materials.

The morphological and structural characteristics of fish adapted to life in the water are that most of them are spindle-shaped, covered with protective scales, and have lateral lines on the body surface. Fish live in water all their lives, breathing with their gills. Fishes move with fins and have not only odd fins, but also even fins.

Fish use their bladders or fins to adjust their body gravity and gain the buoyancy of water.

Two characteristics of fish are crucial to their ability to live in the water: their ability to swim for food and defend themselves against predators, and their ability to breathe in the water.

Fish have a gas-filled sac called a swim bladder, which enables the fish to settle, float, and hold its position in the water, only rays and sharks do not have this organ.

Because the fish has gills, it can filter the dissolved oxygen in the water from the water through this part, so when the dissolution hole in the water is high enough to vibrate and dissolve oxygen, it can live normally, and when the water surface pressure is high in the rainy section, the dissolved oxygen in the water is insufficient, and the fish will not adapt, so as to attach to the water surface.

Take carp as an example: 1. The back is dark gray-black, and the belly is white. This is a protective color.

Second, the body is fusiform (head and tail are pointed, and the trunk is broad) Third, there is mucus on the surface of the fish's body.

Fourth, there are lateral lines (sensory organs) on both sides of the body, and fifth, there are.

1. The body shape of the fish is fusiform, which can reduce the resistance of the water. And the body color is deep back and light belly, which has a protective effect.

2. The body surface of the fish has scales and mucus, which has the effect of protecting and reducing resistance; It also has a lateral line that can determine the direction and sense the flow of water.

3. The fin of the fish is the locomotor organ during the exercise, and the tail fin can stabilize the body, push forward and control the direction; There are swim bladders in the body, which help the fish swim between different water layers.

4. The gills are the respiratory organs of the fish, and the numerous gill filaments in the gills are conducive to the fish taking oxygen from the water.

1 First of all, the body is fusiform, that is, the flowing water type, 2 There are lateral lines on both sides of the body, which can secrete lubricating fluid.

The area of the 3 fins is small, but the strength is sufficient, and while reducing the resistance, it is also the power of **4 breathing with the gills, 5 There are bubbles in the body, just like a submarine.

Hope it helps.

There are gills to breathe in the water, fins and tails to control direction, and fish scales to reduce resistance in edema.