1. First, we can observe the koi’s belly. If the koi’s belly is obviously bigger, it means that the koi is pregnant. Koi usually lay eggs when the water temperature is around 20 degrees, and the obvious characteristic is that their belly is larger than usual.

2. The spawning time is usually in May and June every year. Koi are oviparous and fertilized in vitro. They will not directly give birth to small fish, but will only lay eggs, and the eggs they lay are not fertilized.

3. Fish of 5-6cm generally do not carry eggs. If it is not an "old man fish", the fish may have internal organs problems. Generally speaking, koi fish will not bear eggs until they are 2 years old, and some fish will not bear eggs until they are 3 years old. Even if a 2-year-old fish is kept in a fish tank, it should be more than 20cm long. Usually a 2-year-old fish can reach a body length of at least about 40cm.

4. When laying eggs, the water temperature is usually around 20 degrees. After laying eggs, there will be yellow or white eggs stuck to the tank wall.

How to know whether the koi is full:

1. It is normal for the koi to finish eating in about 10 minutes after feeding. If the feed is eaten up immediately, it will only It means that it is not enough, and some fish are not full. You can also feed a small amount of feed again, or increase it appropriately next time.

2. If it is not finished after 30 minutes and the fish have left the feeding ground, the feeding can be appropriately reduced next time.

3. Especially if the fish is not sick and moves frequently on the water surface after feeding, this is a sign of hunger. On the contrary, fish that are full will leave to play.

4. Especially when young fish or small fish only swim in groups on the water surface, this is a sign of severe hunger, commonly known as "horse racing disease". You must feed them immediately and stop swimming wildly, otherwise they will Massive deaths.