Breeding of carps.
The spawning carp. During unloading wintering ponds is carried out the appraisal of manufacturers. Carp producers must be without any damage. Select females with a very soft abdomen (Nestle). Males select those with soft pressure on the abdomen leaking milk. Such manufacturers take a job in the first place. As a rule, these younger producers — females 4-6 years and males of 3-5 years.
Spawning the carp in special ponds. Before planting, producers to spawn in the spawning ponds they make all necessary preparatory agroforestry work: mow and burn last year’s grass, and the ashes used as fertilizer; loosen the bottom of the pond that contributes to the development of soft meadow vegetation; if the bottom and side slopes of the spawning ponds poor vegetation, draped with turf and with branches of pine, spruce, juniper, etc.
The branches of deciduous trees do not use, as they quickly wither and rot; do not allow the emergence in spawning ponds of pests, frogs, tadpoles, which destroy the eggs and larvae of carp after spawning, reduce the food base of the pond.
Fill spawning ponds with water through the filters, making sure not to expose the eggs and larvae of weed and wild fish, as well as vreditelei ponds and other ponds. Carp spawn when the water temperature is 18-20 C. When water temperature is where the producers, reaches 15-16, start to fill spawning ponds. Filling spawning ponds produce in the morning at 6-7 h, and manufacturers are thrown to spawn in 17-19 hours of the same day. During this time the temperature of the water in the spawning pond should rise by 2-3 °C compared with the temperature of the water of the pond was maintained by the manufacturers.
In no event it is impossible to fill with water spawning ponds for several days before planting to spawn producers, as it leads to rotting vegetation, which females lay eggs, and also created favorable conditions for the reproduction and development of the enemies of eggs and larvae of common carp. Manufacturers choose to spawn with well-developed ovaries. In the spawning ponds manufacturers delivered on a canvas or stretcher canvas in vats of water. The spawning season of carp generally takes place in the morning. It must be ensured that during spawning, no one walked on the dam, to prevent the passage of horse and car or any other transport. Of great importance is the selection of producers in the slot.
The nest consists of one female and two males. By the nature of the spawning carp belongs to the gregarious gathering for spawning in large herds. In the conditions of pond culture distinguish the pair, breeding and group breeding. Pair possibly breeding carp and common carp, used in breeding in breeding farms (one female and one male). Breeding reproduction, taken in practice as the basic, applicable for carp and some other fishes, consists of one female and two males. Group reproduction during the reproduction of common carp, silver carp, tench. For spawning trout in the pond so many females and males. In hatchery practice, it is established that obtaining fry from the female as possible when breeding and spawning group.
The advantage of group spawning is that this method achieves a higher selectivity in fertilization. During spawning, manufacturers often move with noise in the shallow parts of the spawning ponds, on bursts on the surface of the water. Spawning lasts 5-7 hours, but sometimes longer. Spawned by the female, the eggs are immediately fertilized by the sperm and is attached to vegetation, which develops before hatching. After spawning in the late evening or early morning next day manufacturers are caught and transplanted to the nursery grounds in the ponds litemate.
Do it very carefully, so in the period of harvest of the spawning pond not to injure the fertilized eggs, attached to vegetation, and to prevent the spread of disease from producers and eating their larvae. Spawning ponds after harvest, producers filled with water at 15-20 cm above the level during the spawning season to prevent drying of eggs on vegetation that grows, and death of eggs due to sudden water temperature fluctuations.
At a water temperature of 18-22 °C hatching of larvae from eggs is ending in 3-4 days. The larvae have a large yolk SAC which they nourished in the first days of life. The first two days after hatching the larvae are immobile lifestyle, there is a partial resorption of the yolk SAC and the larvae move to mixed feeding. Since that time, the farmers have to be careful, without holding larvae in spawning ponds, must immediately transplant them into nursery ponds.
This is necessary because in spawning ponds water exchange does not occur, insufficient forage base, and existing vegetation rots quickly, resulting in disturbed hydrochemical conditions decreases the oxygen content. All this leads to a significant waste of larvae. Under favorable growing conditions and good producers preparing the spawning ponds can be obtained a considerable number of larvae from 200 to 300 and more than thousand units from one nest depending on the female and her age.
The harvest of the spawning ponds. A critical point is to catch the fry from the spawning ponds. Do so before sunrise or after sunset, preferably on a cloudy day, the third-fifth day after hatching. First of all, harvest the larvae spend on a complete water mill made of gas nets or other fishing gear. Larvae concentrate in floating cages, the bottom of which is lined mill gas or gauze. After that the water gradually people lower.
1. Stocking nursery pond is sure to hold fish, caught from one of the spawning pond, and if multiple, from one-time spawning.
2. Fry stocking of the pond should be done in one day.
3. For more complete dispersal of the fry over the entire area of the pond zaryblyayut it in different places.
If stocking nursery pond stretching over time, the fingerlings will grow uneven hitch, low fatness and during the winter a significant portion of them will die.