Grass carp in a pond, in cages, in a recirculation system - features of breeding and maintenance

 

White carp is a valuable fish for growing in a pond, in cages, in a recirculation system - what are the features of breeding and keeping white carp in aquaculture

Content

• 1 Description of the fish white carp
• 2 Grass carp in a pond - features of breeding and maintenance
• 2.1 Breeding grass carp
• 2.1.1. Grass carp in a pond at the dacha - Growing grass carp in a pond
• 2.2 What to feed grass carp in the pond
• 2.3 How grass carp grows in a pond
• 2.4 Stocking with grass carp
• 2.5 How grass carp overwinters in a pond
• 2.6 How grass carp reproduces
• 3 Grass carp in cages
• 4 Grass carp in RAS
• 5 Literature on growing and breeding grass carp

 

 

Description of white carp fish

Grass carp is a typical river fish and resembles a chub in appearance. The body of grass carp is elongated, cylindrical in shape, slightly flattened at the sides. The color of grass carp is light green, darker on the back and whitish on the belly. The rear, free edges of the scales are dark, the body is patterned, as if dark crescents are placed on it one next to the other. The back of the mouth falls away a little. The pharyngeal teeth are compressed, their crowns are saw-shaped.

 

Grass carp in a pond - breeding and maintenance features

Breeding grass carp in a pond

Growing grass carp in a pond

White carp are easy to breed in large and small ponds, reservoirs, estuaries, sea bays with desalinated water, and rice fields. White carp gets along quite well in polyculture with other fish, such as carp and silver carp, without entering into food competition. Basically, grass carp is a bioreclamation agent of a reservoir, which grows quickly and produces additional products. Therefore, stocking a reservoir with grass carp only is ineffective. Grass carp in a pond at the dacha may well grow together with other species of fish, but like any fish, grass carp requires protection from otters, herons and fishermen, especially since fishing for grass carp is a very exciting activity.

What to feed grass carp in a pond

So what does grass carp eat in the pond? Juvenile grass carp first feed on zooplankton. Reaching a length of 6-10 cm, when the intestines become longer, grass carp switches to plant foods. Grass carp primarily feeds on plant foods. However, like carp, grass carp sometimes eats juvenile fish. Grass carp is unpretentious; in the pond it readily eats food intended for carp. If grass carp becomes addicted to a feeder with carp food, it is difficult to get it out of there. In this case, you can use the following trick - stop feeding the carp for a week, as a result, grass carp will switch to plant food again after a week and the carp can be safely fed further.

You can often hear the question - what kind of grass does grass carp eat in a pond? When asked what kind of grass grass carp eats in a pond, we can say that among the plants grass carp prefers to feed on filamentous grass, soft grass, but it can also eat hard algae, hornwort, duckweed, reed leaves, etc.
Grass carp does not eat the hard stems of the yellow iris, it only partially consumes the hard stems of the cattail, it does not like amphibian buckwheat and the flaccid buttercup. Grass carp loves food that can be obtained without much difficulty, so it prefers thin soft stems, as well as cut leaves of reeds. If there is no favorite food, grass carp becomes indiscriminate: it grabs above-water plants and with one jerk tears them out of the ground. He eats most of them and spits out the rest. Pieces of plants floating on the surface, bitten off at one end, are the result of the “activity” of grass carp.
The optimal feeding temperature for grass carp is 25-30° C. At this temperature, it can eat 100-120% of its weight in food every day. In winter, grass carp does not feed at all.
If there is only tough emergent vegetation in the pond, then grass carp should eat 30-60% of its body weight daily. If there is no vegetation, then you should either reduce the amount of grass carp or feed it. The daily feeding rate is 3-4% of the fish’s weight. As feed, you can use the usual feed mixtures accepted in carp farming.
Grass carp produces significant additional production, so it is a favorable additional fish in a carp pond. In order for grass carp to immediately get used to green food, it should be fed with this food immediately after stocking. If there is no food, then land plants are brought in. An excellent mixture is a mixture of varieties of clover, alfalfa, and forbs that are mowed along the banks of the pond.
Grass carp is capable of very quickly destroying its own food supply (especially in the southern regions). It is advisable to use grass carp in pond farming as a biological ameliorator.

How grass carp grows in a pond

When asked how quickly grass carp grows in a pond, the answer can be that grass carp grows quickly. Hatched grass carp larvae are 5.0–5.5 mm long. At a length of 8.0–8.5 mm, grass carp begins to actively feed. Mass of fingerlings of grass carp with good in pleasant conditions, 40 g, and two-year-olds - 600 g. Three-year-olds reach 1500 g, and four-year-olds - 3300 g. The growth of grass carp depends on water temperature, stocking density and the availability of food.

Stocking a pond with grass carp

Stocking of ponds with grass carp is carried out with fingerlings or two-year-olds.
At the first stage, we equalize the temperature of the water in the container that contains the planting material - white carp fry. To do this, water from the pond is gradually added to the container, thus equalizing the water temperature, and the grass carp acclimatizes to the temperature of the reservoir.
At the second stage, we treat grass carp. To do this, take a container into which water is collected from a reservoir, salt is diluted in this water at the rate of one tablespoon of coarse table salt per 1 liter of water, for grass carp weighing 300-500g. Bathing in a salt solution will save grass carp from dermatomycosis; grass carp is very delicate and during transportation the fish often receives various kinds of abrasions and minor injuries.
The fish are kept in the saline solution for 5 minutes, white carp is a very jumping fish, so in order to prevent it from jumping out of the containers, it is necessary to cover the container with a sheet of plywood or something similar during disinfection.
2 minutes after the start of swimming in a salt solution, grass carp becomes lethargic and calm. In this case, the fish needs to be stirred up and forced to move a little. In 5 minutes in salt water, the mucus should come off the grass carp.
Then we transfer the fish to another container with water from the reservoir so that it begins to move and gets rid of the excess salt that it managed to swallow.
The next step is to release the fish into the pond, the most important thing is not to drop the fish.

Grass carp stocking density (grass carp stocking rate). Stocking density and food availability are interrelated: the more vegetation in the pond, the more grass carp should be stocked. Productivity, depending on the oxygen content in the water and nutrition during the growing period, is approximately 50-1000 kg/ha.
Being together with other fish in the same pond, grass carp should not be a competitor for food. With the correct ratio of carp and grass carp, the carp eats its food, and the grass carp eats green plants. Planting grass carp is then profitable when the productivity of the pond increases significantly.

How does grass carp spend the winter in a pond?

You can often hear the question, will grass carp survive in a pond in winter?
Yes, grass carp can overwinter in a pond. At a temperature of 1-2°C, grass carp tolerates wintering very well in wintering ponds and pits, where it hibernates. A longer stay in the winter hut (until June) is also well tolerated with appropriate feeding. By this time, 10,000–20,000 fingerlings of grass carp can be kept on every 1000 m2, since the wintering area is free from vegetation. With a short winter, grass carp can overwinter in a pond 1.5 meters deep.

How does grass carp reproduce?

Questions are often asked: does grass carp reproduce on its own in ponds? Is it possible for grass carp to spawn in a pond?
You shouldn’t bother with the reproduction of grass carp in an amateur pond; grass carp reproduce quite difficultly even in fish farms; it is easier for a simple fish farmer to buy planting material at the nearest fish farm.

Grass carp in cages (breeding grass carp in cages)

Growing grass carp in cages is quite possible, this is confirmed by experiments conducted back in Soviet times, as well as the experience of Russian and Kazakh fish hatcheries. Grass carp tolerates cage conditions well. During storms, it does not get motion sickness, it is not depressed by a sharp change in salinity; experiments have shown that grass carp can withstand salinity up to 9%. But growing grass carp in cages as a monoculture is not profitable. Grass carp as a bioreclamation agent can be added to cages with other fish, a few pieces per cage. Grass carp cleans cages of fouling, improves the flow of cages and provides additional production without the cost of feed.

Grass carp in RAS (breeding white carp in RAS)

Growing grass carp in a RAS is quite possible, but not profitable from an economic point of view. The basis for the profitable production of grass carp is the absence of costs for feeding it, despite all its other positive qualities.