The Chinese sturgeon is a fish
The Chinese sturgeon is a very precious animal living in our country, and it is also one of the animals under key protection in our country. Since they belong to the class Teleost, they are a type of bony fish and naturally belong to fish. From the specific classification point of view, the Chinese sturgeon belongs to the sturgeon. The sturgeon itself contains many species, and the Chinese sturgeon can be said to be a very precious one among them.
The difference between Chinese sturgeon and sturgeon
1. Appearance characteristics
Chinese sturgeon: Chinese sturgeon has an elongated body with tapering ends, a narrow back and a narrow abdomen. Straight. The head is long triangular in shape. The tip of the muzzle is long. The nostrils are large and located in front of the eyes. Blowholes are cracked. The eyes are small, oval, located in the back half of the head. The eyes are widely spaced. The mouth is inferior, transversely cleft, protruding, and can expand and contract.
The lips are underdeveloped and have small papillae. There are two pairs of whiskers in the center of the muzzle, arranged in an arch shape. Their length is shorter than 1/2 of the distance between the whisker base and the front edge of the mouth, and the outer whiskers do not reach the corners of the mouth. The gill slits are large and the false gills are well developed. Gill rakers are sparse and short and thick. 1 dorsal fin, posterior position, concave trailing edge, starting point in front of the anal fin. The anal fin is opposite to the dorsal fin, below the middle of the dorsal fin.
The pelvic fin is small, rectangular, located behind and below the center of the body, close to the anal fin. The pectoral fins are well developed, oval, and low in position. The caudal fin is crooked, the upper lobe is particularly developed, and there is a longitudinal row of spinous scales on the upper edge of the caudal fin.
Sturgeon: Sturgeon is a rare ancient fish left over from the Mesozoic Era 150 million years ago. It is between cartilage and hard bone. The degree of ossification of the bones is generally reduced, and the central axis is undeveloped. Ossified elastic notochord, no vertebrae, and most of the cartilage shell accompanying the skull is not ossified. The caudal fin is crooked, the even fins have a broad base, and the dorsal fin is opposite to the anal fin.
The pelvic fin is located in front of the dorsal fin. The bases of the fin and caudal fin have spinous scales. The intestines have spiral valves. The anus and cloaca are located near the base of the pelvic fin. The opening of the fallopian tube is far away from the ovary.
2. Life habits
Chinese sturgeon: The Chinese sturgeon is powerful in shape, large in size, and has a long lifespan. The longest lifespan can reach 40 years old. It is the largest individual among freshwater fishes. , the longest-lived fish. After the Chinese sturgeon enters the river, it must stay in the river for one year and arrive at the spawning site in October of the next year.
During this year, the Chinese sturgeon did not always swim up the river, but stopped and lurked in the potholes of the river for several days without moving. In the autumn of the second year, they go upstream to the river section with fast currents and gravel bottom to breed. The breeding groups gather at the spawning ground to breed.
The Chinese sturgeon is a bottom-dwelling fish. It is an omnivorous fish that mainly feeds on animal food. It mainly feeds on some small or slow-moving benthic animals, including shrimps, crabs, fish, Molluscs and aquatic insects, etc.
Due to the different food types in different living environments, juvenile fish mainly feed on chironomid larvae, dragonfly larvae, mayfly larvae and plant debris in the middle and upper reaches of the Yangtze River. Young fish in the area feed on shrimps, crabs and small fish. Broodstock do not feed during migration.
In the coastal waters outside the Yangtze River Estuary, the feeding intensity of Chinese sturgeons increases, usually at level 3-4. Their food is mainly fish and crabs, as well as shrimps and cephalopods.
Sturgeon: Sturgeon is a bottom-dwelling fish with a very narrow feeding habit. It is a carnivorous fish. In the river, it mainly feeds on some small or slow-moving benthic animals. In the ocean, it mainly feeds on fish. Food is mainly species, followed by crustaceans and less molluscs.
3. Distribution range
Chinese sturgeon: The Chinese sturgeon is the only species of the Acipenidae that crosses the Tropic of Cancer. It was once mainly distributed in the coastal areas south of the west coast of the Korean Peninsula and various regions. Large rivers, from the main stream of the Yangtze River in China, from the Jinsha River to the mouth of the sea, other water systems such as the Ganjiang River, Xiangjiang River, Minjiang River, Qiantang River and Pearl River water systems occasionally appear, with the Yangtze River producing the most.
Sturgeon: Sturgeons are now mainly distributed from the Jinsha River, the main stream of the Yangtze River in China, to the estuary of the sea. They occasionally appear in other water systems such as the Ganjiang River, Xiangjiang River, Minjiang River, Qiantang River and Pearl River water systems. Abroad, it is found in the Han River Estuary and Lijiang in North Korea and the west side of Kyushu in Japan.