How is the goldfish turning black?

The blackening of goldfish may be due to the deterioration of water quality.

When the water quality is poor or polluted, the water can contain a lot of toxins, which will cause pathological changes, malignant changes and skin canceration and blackening of goldfish. If this is the case, it is necessary to change the water for fish farming in time. In addition, it is normal for goldfish to turn black locally when they give birth during pregnancy.

Goldfish originated in China, also known as "golden crucian carp", which is similar to carp, but has no mouth whiskers. It is an ornamental fish evolved from crucian carp. There are many varieties of goldfish, including red, orange, purple, blue, ink, silvery white, five flowers and so on. , divided into four categories: literary species, grass species, dragon species and egg species. 12 century, the genetic research of goldfish domestication began. After a long period of cultivation and continuous optimization of varieties, goldfish from all over the world are now directly or indirectly introduced from China.