How Are Koi Scored? A One-Minute Guide to the Life and Breeding Habits of Koi

KoiThe suitable water temperature is 5—30°C, with the optimum temperature being 20—25°C, but they are not very adaptable to rapid changes in water temperature.

If the temperature rises or falls by more than 3°C, the fish will become ill; if it exceeds 10°C, the fish will die.

Koi can be kept in water with a pH of 6.8—8.0, but they are best suited to weakly alkaline, low-hardness water with a pH of 7.1—7.3.

Koi grow slowly under strong sunlight, so a shade awning can be set up at the pond corner or at the feeding spot.

Koi are omnivorous; generally, mollusks, aquatic plants, benthic animals and tiny algae are all delicacies for koi.

Koi eat more in summer and eat less or almost nothing in winter. Therefore, feeding can be increased or decreased depending on the season.

In spring, when the water temperature is above 12°C, bait can be given 3 times a day; when the water temperature drops below 12°C, feeding only once a day is enough.

Breeding Habits

Male koi reach sexual maturity at 2 years of age, and females at 3 years of age. They fertilize externally and lay adhesive eggs. The eggs are white or pale yellow, about 2.5 mm in diameter. They spawn once a year, and the spawning period is generally concentrated in April—June. Sexually mature females usually spawn between 4 and 10 in the morning.

The eggs form fertilized eggs through external fertilization, and the fertilized eggs attach to aquatic plants, artificial spawning nests or other attachment surfaces to develop. After 4—5 days of incubation, the fry hatch out of the shells;

Or artificial breeding can be used for fry rearing, which can increase fry output. Newly hatched fry can be fed rotifers, small cladocerans or crushed egg yolk.