Goldfish originated from wild crucian carp, which is directly or indirectly mutated from wild crucian carp. This view has been widely accepted by Chinese and foreign biologists and goldfish breeders. It is confirmed by experimental research and my country's rich scientific historical materials. However, the body color of the crucian carp is a single silver gray or black gray, the tail fin is single tail, the body shape is flat and narrow, and the eyes are small... Why is the goldfish colorful and colorful? There are two tails, three tails, four tails, long tails, vertical tails, butterfly tails, fan tails...? Why do goldfish have flat, square, and round heads? Do you have bulging eyes, flat eyes, sky-looking eyes, or blisters? Can there be such a big difference between the two? yes. The great evolutionary scientist Darwin once said; The species of plants and animals are not fixed, but changeable, Variety with various distinctly different characteristics can originate from a common ancestor, Species in human intervention The following can be changed.” Engels pointed out: After artificial cultivation, plants and animals have changed their appearance under the hands of man, and they can no longer even recognize their original appearance. So do goldfish. During the process of pond culture and pot culture, the external living environment has changed greatly: the living space has become smaller, the feed is completely dependent on artificial supply, and people's conscious artificial selection, as well as hybridization and genetic breeding, have changed the external form of goldfish. Countless new varietals. However, aside from the different colors and shapes, we will find that they have a certain blood relationship with each other-their common ancestor is the ancient wild crucian carp, which belong to the same order Cyprinidae, Cyprinidae, and crucian carp, and have the same scientific name. .      This is because:

1 Any species of goldfish can mate with crucian carp to produce fertile offspring.

2 The embryonic development of goldfish and crucian carp is exactly the same, with some differentiation only in the postembryonic stage.

3 Both goldfish and crucian carp have 47 pairs of chromosomes and the same shape in the nucleus during embryonic development.

4 The serum precipitation reactions of goldfish and crucian carp were identical. Therefore, people say that crucian carp is the ancestor of goldfish, and goldfish evolved from wild crucian carp.      What are the main fish diseases of goldfish in winter?

Few fish diseases generally occur in winter. Winter is the period for the stocking of fingerlings, often due to nets or transportation scratching the fish, saprolegnia can also occur; when the water temperature is high, there may be cholangioplasmosis and small melon worm disease.