Bream fish farming in aquaculture

Bream is a valuable commercial fish; bream is distributed throughout Europe and is acclimatized in the waters of Asia. Bream can be widely grown in rivers and lakes, and in ponds.

Content

• Characteristics of bream as an object of fish farming
• What does bream look like?
• Where does bream live?
• Bream spawning
• Artificial spawning grounds for bream
• Bream feeding
• Bream growth
• Obtaining bream offspring using the spawning and rearing method
• Reproduction of bream by spawning and growing method in the Don River
• Features of growing bream in a pond

 

Characteristics of bream as an object of fish farming

What does bream look like?

The body of the bream is high (height up to 1/3 of the length), which is laterally compressed. The bream has a small head and a short snout; the mouth is semi-inferior, small, ending in a retractable oral tube. Behind the pelvic fins there is a keel not covered with scales. The anal fin begins under the posterior edge of the base of the dorsal fin. In spawning males, spots appear on the sides of the body below the lateral line, above the back of the anal fin. The pharyngeal teeth are single-rowed. The back is dark brown or grayish, the sides are golden brown, silver in juveniles, the belly is yellowish. The fins are dark, or light brown, or gray.

Where does bream live?

In what waters does bream live, where does bream live? Bream is a freshwater, usually lake and river fish, which prefers not very fast flowing or stagnant waters. In the Azov and Caspian Seas, bream is a semi-anadromous bottom fish that reaches a length of 30-40 cm and an average weight of 2.5-3 kg. In the seas, bream is common in desalinated areas of the sea with a depth of up to 4-5 m. Bream is also found in the bays of the Baltic Sea. The maximum length of bream is about 80 cm and weight 9 kg. The lifespan of bream is up to 13–17 years.

Bream prefers to live in reservoirs with muddy or sandy-silty bottoms; bream does not like cold or fast water. The favorite habitat of bream is deep places, clay pits. Only in cloudy weather, as well as in hot weather, does bream rise to the surface of the water. Bream gather in large schools and remain in a school for most of the year.

In early autumn, bream leaves their feeding areas and gathers in winter stops, choosing quiet and deep places for this. In deep places, bream hibernate.

Bream spawning

Males of bream mature in the 3rd year, females in the 4th year of life, the absolute fertility of bream varies widely - 60-900 thousand eggs, the working fertility of bream - 100 thousand eggs. Female bream are most fertile at the age of 5-7 years. The diameter of the ovulated egg is 1.0-1.5 mm.

In spring, bream enters rivers to spawn. Spawns in May-June at a water temperature of 17-20°C. As a rule, young individuals spawn first, older individuals spawn a little later, when the water warms up better. For spawning, bream gather in large numbers after sunset, and therefore, closer to night, a strong noise is heard from the splashes of water that spawning bream produce. Bream lay their eggs on aquatic plants. The eggs are sticky and attach to plants. The duration of egg development at a water temperature of 11–16° C is 10–11 days, at 22° C – 2–3 days. After hatching, the prelarvae remain in the resting stage for two days, attached to aquatic plants; The yolk sac dissolves within 3–4 days. After this, the larvae migrate to the open parts of the reservoir and switch to active feeding.

 

Artificial spawning grounds for bream

Artificial Bream Spawning Beds - The most common type of bream spawning beds are floating frame spawning beds which are used in rivers, reservoirs, lakes and ponds. Spawning grounds for bream are made in the form of a wooden frame with a plant substrate on leashes (as shown in Figure 27). To create a spawning ground, it is necessary to prepare a substrate - brooms from spruce branches of coniferous trees, this is the simplest and most effective material.
Brooms tied from spruce branches are attached to a leash made of twine and then attached to a floating frame measuring 10x1 m made from wooden poles. The length of the leash is calculated based on the depth of the spawning site, usually 3-6 m. Approximately 50 vertical tiers with 300-750 brooms are placed on the bream spawning site in the form of a floating frame; approximately 40-100 million bream eggs are placed on these brooms. An artificial spawning ground for bream creates dense underwater thickets on which the bream lays eggs.
Coniferous brooms with fertilized bream eggs can be transported to another reservoir for the purpose of stocking this reservoir with fish.
Such floating spawning grounds allow fish farmers to widely use them in various types of reservoirs, especially in reservoirs where the water level varies greatly.
The counting of eggs laid on floating spawning grounds is carried out on ten control brooms with different egg laying densities. To do this, these coniferous brooms are washed from silt, the brooms are weighed one at a time and then lowered back into the reservoir. After the larvae hatch, the brooms are washed again, and then weighed according to the difference. The mass of live eggs is calculated in the mass of brooms. In order to determine the total mass of eggs on the spawning ground, it is necessary to multiply the average mass of eggs on one coniferous broom by the total number of coniferous brooms. 1 kg of bream caviar contains about 230 thousand eggs at the eye stage.
Artificial spawning grounds are effectively used by both bream and other fish. The egg laying density is 150 thousand - 240 thousand bream eggs per 1 m2 of spawning ground.

Bream feeding

What does bream eat, what is included in the diet of bream? Bream is a benthophage that eats worms, mollusks, crustaceans, some algae, and insect larvae. The most intense feeding and, as a result, faster growth begins after spawning (June - July).

The bream feeds by extracting food from the silt, and does this by sucking in larvae and insects along with the silt. Bream is its predator, but can eat molting crayfish and also eat the eggs of other fish.

Bream growth

How fast does bream grow? The growth of bream is most intense in well-warmed reservoirs: in the 1st year it reaches 20 g and a length of 8 cm, in the 2nd year - 120 g and 20 cm, in the 3rd year - 400 g and 25 cm.
By obtaining offspring, bream are obtained by spawning and rearing method

The offspring of bream are obtained by spawning and rearing method. Usually, together with bream at a temperature of 13-22°C, other fish go to spawn - carp, pike perch, ram. Bream producers in spawning ponds or large reservoirs of 100-1000 hectares find suitable conditions for laying eggs. Juveniles weighing 2-3 g roll down with the escaping water. Bream spawners are brought into spawning ponds in containers - cars or slots. The average length of a bream - producer - is 30-35 cm, weight is 0.7-0.8 kg. The incubation period lasts 9 days at a temperature of 13°C and 5 days at 16-17°C.

After resorption of the yolk sac, bream larvae begin to intensively feed on zooplankton (Copepoda, Cladocera); upon reaching a length of about 30 mm, juvenile bream switches to feeding on benthic invertebrates.

Reproduction of bream by spawning and growing method in the Don River

For the reproduction of bream in the Don River, the following standards have been adopted: the average fertility of bream is 100 thousand pieces, the survival rate of juveniles from eggs to fingerlings is 10%, the average weight of juveniles is 0.3 g. Planting bream breeders in a monoculture per 1 hectare - 15 nests, in polyculture - 8. Grown-up juveniles at the age of 1 month. weighing 200 g are released into water bodies for feeding for 3-4 years, when the bream reaches marketable weight.
The planting density of fingerlings for rearing is 150-200 thousand/ha, two- and three-year-olds in polyculture with other fish - from 10 to 1 thousand pieces. depending on the food supply.

Standards for the reproduction of Don bream using the spawning and rearing method

Yield of fingerlings per 1 ha, thousand pcs.  80-90

Egg survival rate, %   

larvae  25

young of the year  10

Yield of fingerlings from 1 nest, thousand pcs. 9

Average weight of fingerlings, g 0.5

Number of nests per 1 ha, pcs.  200

Producer survival rate, %  90

Working fertility, thousand pieces  90

Manufacturers reserve, %  10

Spawning area, ha  up to 1

Area of the nursery pond, ha up to 200

Average depth, pond m  1.5

Features of growing bream in a pond

Bream can be raised in ponds, but sometimes when raised in ponds, bream can form a slow-growing population. Research conducted in Kazakhstan has shown that, as a rule, a slow-growing population of bream is formed in lakes where there is a wide strip of shallow water and the reservoir is not completely fished. When growing bream in a pond where there are no large shallow waters that warm up well and the reservoir is completely fished, the bream grows well, without the formation of a slow-growing population.

Bream can be used for grazing in rivers, lakes, ponds, sea estuaries and desalinated bays; as a rule, it is enough to create conditions for good spawning of bream.
Bream is also a desirable object in sport fishing, so you can grow bream in ponds that are intended for paid fishing and in ponds for complex purposes, for more complete use of the food supply, where bream can subsequently be the object of sport and paid fishing.
Growing bream in polyculture has so far been poorly studied, but Kazakhstan's experience shows that bream should not be bred in polyculture with peled.

A polyculture of bream with carp is considered more promising, where carp is the main object of cultivation, and bream is grown as an additional object.

A polyculture of bream with pike perch is used, where pike perch is grown as an additional object that destroys trash fish; it cannot eat bream because of its high back, and bream is the main object of cultivation.

a polyculture of bream with carp and pike perch is used.