The Function of a Fish's Tail and an Introduction to Common Fish Species

Fish are animals of the subphylum Vertebrata within the phylum Chordata, and are among the most ancient. Fish live in almost all freshwater lakes, rivers, and oceans on Earth. More than 30,000 species of fish have been discovered so far, and China has 2,500 species. Most fish are cold-blooded animals, and only a few are warm-blooded. They breathe with gills, and most die once they leave the water. Fish have a pair of nimble tails, so what function does a fish's tail have? What are the common species?

1. What function does a fish's tail have?

A fish's tail can maintain the body's balance, but it must work together with the fish's pectoral fins to propel the body forward and control direction properly. If a fish loses its tail, its body will tilt forward and it will be unable to swim normally.

The tails of different species of fish also differ to some extent. For example, the tail of the guppy can attract the gaze of the opposite sex and is a powerful tool for mating.

2. What are the common species of fish?

If fish are divided into groups according to water type, they can be classified into freshwater fish and saltwater fish. Let's take a look at some common species below.

1. Crucian carp

Distributed across the north and south of the country, it is omnivorous, gentle in nature, prefers warm and cold water systems, and is active in the middle and lower layers of the water. It has strong adaptability, and wherever there is water, there are traces of crucian carp. Crucian carp is also a type of fish very much loved by anglers. Its flesh is tender and its nutritional value is relatively high, but it simply has quite a lot of bones.

2. Snakehead

It is widely distributed. Rivers, lakes, ponds, ditches, bays, small ponds, and grassy ponds are all areas where it is active. Fujian, Yunnan, Jiangxi, Guangdong, Zhejiang, Taiwan, China, Southeast Asia, and other places are all habitats for it. It has more than a dozen related species. It can live for three days out of water. Its flesh is tender, and it is a food ingredient well known both domestically and abroad.

3. Mandarin fish

The vast areas of East China and South China are its places of life and reproduction. It is often active in the lower layers of the water, prefers warm water, is phototactic, and is a carnivorous fish. Fujian, Zhejiang, Jiangxi, Hunan, Hubei, and Sichuan all show traces of it. The flesh of mandarin fish is delicate and rich in nutrients.

4. Catfish

It is relatively widely distributed in China and is active in the lower layers of the water. Most areas of Central China, South China, and East China provide living space for it. It prefers warm and cold water systems, is a carnivorous fish, likes to eat carrion, is fierce in nature, and is full of strength. It is mostly found in East China and South China, and is distributed in Taiwan, China and Southeast Asian countries as well.

5. Tuna

Tuna is a large, important oceanic commercial food fish. It is expensive, and much of it is made into canned goods and sold around the world. At present, China mainly relies on imports for it.

6. Hairtail

The hairtail's body is laterally compressed like a belt and is silver-gray. Its dorsal fin and pectoral fins are light gray with very tiny spots. The hairtail is rather fierce, but its nutritional value is very high, and it has the effects of warming the stomach, tonifying deficiency, nourishing the skin, dispelling wind, killing parasites, and supplementing the five internal organs.

7. Squid

Squid, also known as soft squid or arrow squid, is often active in the upper and middle layers of shallow seas, and its vertical movement range can reach more than 100 m. Squid has very high nutritional value, tastes delicious, and has chewy flesh, and is deeply loved by consumers.