What is the function of a fish's tail? What are the common varieties?

Fish is a subphylum of vertebrates in the phylum Chordata, and it is the oldest one. Fish living in almost all the freshwater lakes, rivers and seas on earth, more than 30, 000 species of fish have been found, and there are 2500 species in China. Most of the fish are cold-blooded, only a few are warm-blooded, they breathe through their gills, and most of them die when they leave the water. The fish has a pair of smart tails. What is the use of the fish's tail? What are the common varieties?

What is the function of the tail of a fish?

The tail of the fish can maintain the balance of the body, but to match the pectoral fin of the fish, it can push the body forward and control the direction. If a fish loses its tail, its body will lean forward and cannot maintain its normal swimming.

There are still some differences in the tails of different species of fish. For example, the tail of peacock fish can attract the attention of the opposite sex and is a sharp tool for mating.

What are the common species of fish?

Fish can be divided into freshwater fish and saltwater fish according to the type of water. Let's take a look at some common species.

1. Crucian carp

Distributed in the north and south of the Yangtze River, it is omnivorous, mild, warm and cold water system, active in the middle and lower layers of the water, strong adaptability, where there is water, there are traces of crucian carp. Crucian carp is also a kind of fish that anglers like very much, with delicate meat and high nutritional value, but with more thorns.

2. Black fish

Widely distributed, rivers, lakes and ponds, ditches and bays, blisters, and Caotangzi are all areas of its activity. Fujian, Yunnan, Jiangxi, Guangdong, Zhejiang, Taiwan, Southeast Asia and other places belong to its habitat, it has more than a dozen species of the same kind, can live three days away from water, delicate meat, is a well-known food at home and abroad.

3. Mandarin fish

The vast area of East and South China in China is its living and breeding place, often active in the lower layer of the water, like warm water, light, carnivorous fish, Fujian, Zhejiang, Jiangxi, Hunan, Hubei, Sichuan all have its shadow, mandarin fish meat is delicate, nutritious.

4. Catfish

It is widely distributed in China, and its activities are in the lower layer of the water. It has its living space in most areas of Central China, South China and East China. It likes warm and cold water system, carnivorous fish, likes to eat rot, ferocious and energetic, mostly in East and South China. Taiwan and Southeast Asian countries are distributed.

5. Tuna

Tuna is a kind of large ocean-going important commodity edible fish, which is of high value. Many of them are canned and sold all over the world. At present, China mainly depends on imports.

6. Belt fish

The side of the belt fish is flat, silver-gray, the dorsal fin and pectoral fin are light gray, with very small spots, the belt fish is ferocious, but the nutritional value is very high, which has the effect of warming stomach, tonifying deficiency, moisturizing skin, dispelling wind, killing insects and tonifying the five internal organs.

7. Squid

Squid, also known as squid and squid, is often active in the middle and upper layers of the shallow sea and can move vertically over a range of more than 100 meters. Squid has high nutritional value, delicious taste, chewy meat, and is deeply loved by consumers.