1, insufficient oxygen. The suitable temperature range is 2℃ ~ 30℃, but it can't resist the sudden change of water temperature. When the temperature difference suddenly exceeds 2℃ ~ 3℃, koi fish will feel uncomfortable. The optimum water temperature is 20℃ ~ 25℃. It needs sufficient oxygen and is suitable for living in a slightly alkaline and low hardness water environment.
2. The reason of water quality. The deterioration of water quality environment, the sudden change (instability) of pH value and temperature of water quality, or the lack of dissolved oxygen in water and the existence of chlorine in large quantities will all affect koi fish's normal life. Because the water quality environment is not up to standard, koi fish will get sick, and he will lie motionless at the bottom of the tank. If the situation is serious, koi fish will die.
3. koi fish is ill. As we know, gill rot, tail rot and white spot disease are all common diseases in raising aquatic animals, which have a fatal impact on aquatic animals. Koi fish can't swim and eat normally when he is ill. He can only lie on the bottom of the water and breathe hard. Note that if fish's illness is not treated in time, once it gets worse, it may threaten koi fish's life.
2. Edible requirements: koi fish is an omnivorous fish, and general mollusks, fragments of higher aquatic plants, benthos, even tiny algae or synthetic granular bait can be eaten.
Fish species selection: Fish species with healthy body, no trauma, no desquamation and other diseases, bright body color, diverse colors and clear boundaries should be selected.
4. Feeding density: For general stocking fish ponds, please refer to the koi fish density table of stocking fish ponds; The density of water cluster box is generally 60 cm× 30 cm× 15 cm, and 6 koi fish plants with body length 15 cm ~ 20 cm can be stocked. 8 can be stocked in 90 cm× 30 cm× 50 cm; 110cm× 30cm× 50cm can be stocked10 tail.
Extended data:
1. Check all parts of the fish.
Whether there are pests in koi fish, observe whether there are rotten fins, rotten mouths, perforations, loose scales, erythema and color variation.
Observe whether the fish is getting thinner, which is caused by malnutrition.
Observe whether the fish body is edema and whether the abdomen is drooping, which is caused by the fact that the female fish can't lay eggs and stay in the abdomen to rot. Fish will get pinecone disease when it is swollen, which is obviously caused by internal organs.
Observing whether the fish is bent is often caused by improper or excessive medication.
Observe whether the eyeball is normal. If it is abnormal, it is mostly caused by visceral diseases. Don't find it too late, there is no cure for eyeball collapse.
Check your swimming style.
When koi fish is healthy, he will swim in all directions. When he is ill, koi fish will swim alone. When he is seriously ill, he will stumble and even have no strength to stop swimming and even hit the wall of the pool.
Koi fish forms a circle in the corner of the fish pond or rubs the wall or bottom of the pond with his body, indicating that parasites have been attached to the fish. In severe cases, koi fish rubs his body, slaps his dorsal fin and pectoral fin, or jumps. If koi fish swims standing on his dorsal fin, it is generally a sign of nervous system diseases. Koi fish's winding body is an abnormal signal of koi fish. Staying still on the water is a danger signal. Being unable to stand upright is a state of losing balance. There may be something wrong with the swim bladder, or there may be parasites on the head. When he is seriously ill, koi fish will swim around.
Check your appetite.
Koi fish lost his appetite when he was ill. Try to observe the situation when feeding until you finish eating. Be careful not to let the leftovers sink and rot, which will affect the water quality and accelerate the occurrence of fish diseases.
There are many reasons for anorexia, such as hypoxia, ammonia increase, water temperature change, parasitic infection, virus infection, visceral diseases and so on.
References:
Baidu Encyclopedia-koi fish