Herbivorous fish: names, features of cultivation and nutrition. fish farm

2024 Author: Howard Calhoun | [email protected]. Last modified: 2024-01-17 18:37

Cultivation of herbivorous fish or maintenance of ponds is the main source of fish on the country's commercial shelves. Pond fish farming technologies are developing and changing due to changes in the historical, political and economic situation in Russia.

The pond rearing cycle for carp and other herbivorous fish traditionally takes two to three years. Feeding herbivorous fish in the ponds is carried out by breeding polyculture and fertilizing the ponds. Refusal to use artificial feed with mineral fertilizers allows you to get an annual increase in all types of ponds (nursery and feeding).

Species of herbivorous fish

Which fish are herbivores? The list of herbivorous fish in Russia includes:

• Silver carp white and mottled.
• Carp.
• White Cupid.

These fish, due to their natural characteristics, easily take root in many countries, while maintaining taste characteristics.

White carp

This commercial fish belongs tocarp family and is characterized by rapid growth. There are known cases of weight gain by grass carp up to 50 kg. Any vegetation of reservoirs, meadow grasses, as well as concentrate feed is suitable for feeding cupid. The diet of grass carp is determined by its age.

Age of fish	Menu
1-14 day life	zooplankton
15-30 day life	Small algae
A month or more	Duckweed and other pond vegetation

The amount of food consumed by grass carp often exceeds its body weight.

Cupid is called the natural filter of the pond. The algae eaten by him pass through the intestines of the fish and again find themselves in the reservoir, creating comfortable conditions for living and breeding for other fish. The number of reclamation fish depends on how much the pond is overgrown with algae and ranges from one hundred to five hundred units of grass carp per hectare.

To increase productivity, it is recommended to introduce feed from perennial grasses into the diet of fish. Alfalfa or sainfoin will do. With low vegetation in the pond, grass carp can feed on mixed fodder for some time. But they should not be abused. This can lead to the development of serious pathologies in the population.

Readiness for reproduction in white carp depends on the region of residence. Thus, in the southern regions of the country, grass carp reaches puberty at five years old, and in the northern regions at eight.

With white boostup to 600 cupids per 1 hectare, weakly overgrown reservoirs can be cleared. For moderately and heavily overgrown ponds, the number of grass carp should be increased to a thousand individuals per hectare. The introduction of young grass carp helps to clear unprofitable water bodies overgrown with reeds in one vegetative period and prepare them for growing carp fry.

But in order for grass carp to prove himself as a reclamator of a water area, he needs to create special conditions. So, the depth of the pond should not be less than half a meter. This condition is necessary for fish for a successful wintering. And to ensure the heating of water in the summer months up to 18 ° C.

The technology of growing planting stock of herbivorous fish in complex ponds is based on polyculture. Such representatives of the fish world as silver carp (white and motley), carp, pike and pike perch get along well with white carp. Why can the number of herbivorous fish be sharply reduced? The presence of pike in the pond guarantees that it will eat young grass carp. Therefore, in order to successfully clean the reservoir from algae, two-year-old grass carp weighing over two hundred grams are planted.

This technology has been successfully used by the Saratov fish hatchery of herbivorous fish for a long time. After replanting 2-year-old and 3-year-old grass carp, the enterprise managed to get rid of algae and reeds on an area of more than a thousand hectares, which, in turn, led to an improvement in production and financial performance.

Carp

Karp is the first name that comes to mind when answering the question whichbony fish is herbivorous. In fact, carp is a tamed carp. A characteristic feature of its digestive system is the absence of a stomach. Therefore, the carp devotes its entire life to finding food. Fortunately, it is unpretentious in food - the carp absorbs algae and other aquatic vegetation, insect larvae, midges and small plankton with equal pleasure.

Carp is a long-lived fish, it can live for about half a century. Of course, it makes no sense to grow carp for such a long period of time.

Carp is the most popular species on fish farms. Carp farming accounts for up to 70% of all herbivorous fish.

The popularization of breeding these fish is caused not only by the variety of what carp eats, but also by its undemanding care and maintenance. This fish easily endures difficulties and hardships - cold temperatures and lack of oxygen.

There are three main subspecies of carp:

1. Mirror.
2. Scaly.
3. Naked.

These subspecies branch out into many breeds. There are ornamental types of carp (such as Koi carp) that are bred for aesthetic purposes.

Habitat

Mainly carp are bred in private ponds or rates. Carp fry are as unpretentious as adults. Cages are lowered into a pond with stagnant or low-flowing water - frames on which a mesh is stretched. And fish live and breed in them.

The optimal depth of the pond for keeping carp is one and a half to two meters. shallow depthpromotes good heating of water. It is recommended to install an oxygen generator to saturate the reservoir with oxygen and a backlight for the dark time of the day. Night lighting will attract insects, which feed on carp.

With a balanced menu and proper care, carp fry, weighing 30 grams per season, gains weight three times. And by October, his weight is up to a kilogram.

White carp

Best of all, the silver carp is adapted for living in the southern regions. In a day, this fish eats an amount of food equal to half its mass. Thanks to such congenital gluttony, the weight of a silver carp can reach twenty kilograms.

He gets along well with other herbivorous fish, as his diet does not compete with theirs.

The diet of silver carp is shown in the table below:

Age of fish	Diet
Birth to 9 days	Nauplii, small plankton
From 9 days to a month	Phytoplankton
Adult	Rotifera, small crustacean, detritus

The reclamation abilities of the silver carp are indispensable for eutrophic ponds. Sexual maturity in silver carps depends on climatic conditions: in the southern regions they are ready to breed at the age of 5, and in the northern regions at 8.

Motley silver carp

Different from its whitefellow with a shortened body and a huge head and a well-developed filtration apparatus of the gills.

Like the white, the bighead carp eats up to half of its own body weight a day. For the first two weeks, the fry feeds on one small plankton, eventually moving on to larger algae. Adult bighead carps prefer blue-green phytoplankton.

This species of silver carp grows the fastest, the weight of an adult fish can reach up to 40 kilograms. However, with an increase in population, bighead carps compete with carps. The sexual maturity of these fish does not depend on the habitat and occurs on average at the age of five.

Fish polyculture

At the moment, most fish farms have switched to intensive rearing technology, which is called pasture fish farming. A characteristic feature of such fish rearing is the use of several fish polycultures. The calculation of the density of planting material for various types of herbivorous fish in this case depends on:

• Natural fish productivity.
• Mineralization of the reservoir.
• Feeding ration.
• Age of fish.
• Fish sizes.

Ideal conditions for productive breeding of herbivorous species of commercial fish, as well as for small marine fish, is the rapid warming of the reservoir. This allows you to increase the temperature of the pond water to the optimum values - over 20 ° Celsius - for feeding fish. Given the natural temperature regime of three summer months -the best time for fish to breed.

Place to grow fry

Carp larvae and fry of other herbivorous fish spend their entire "childhood" in recirculating water supply systems (RAS) for growing fish - incubation devices that promote the growth of young animals (VNIIPRKh). The density of the number of fry in a RAS for fish rearing is directly proportional to their mass, and on average is about two hundred and fifty thousand larvae per cubic meter. Then the grown fry are transferred to specially equipped containers - pools or trays.

Features of feeding carp and herbivorous fish

What to feed the fish? This is the main question of a caring owner interested in the growth of young animals. That is why it is so important to take the time to study the distinctive feeding habits of different types of herbivorous fish, their nutritional relationships, as well as the time to transfer fry to specialized food.

Starting food for larvae and fry of herbivorous fishes is feed RK0SZM or its equivalent - "Ekvizo". The composition of this compound feed includes:

• Microbiosynthesis products with high protein concentration.
• Low fat fishmeal.
• Vegetable oil.
• Multivitamin Blend
• Wheat flour.
• Sodium caseinate.

After the weight of the young animals reaches 100 mg, they are transferred to feeding with mixed feed STRAS - 1. The percentage of the composition of STRAS -1:

• Proteins - 55%.
• Fat - 7%.
• Carbohydrates – 16%.
• Water -10%.

For better digestibility, about 50% of the protein compounds that make up the compound feed are destructured. The use of starter feed for fry of herbivorous fish is allowed after switching to external feeding. The frequency of feeding in incubators is from 20 minutes to half an hour. A single portion is distributed evenly in the area of fry accumulation. It is recommended to feed the larvae only during the daytime.

Compound feed RK-SMZ, "Ekvizo" and STRAS-1 are designed for feeding fry in the absence of natural food. To adapt the fry to the natural habitat, it is necessary to add small forms of phytoplankton to the incubators with fish. The presence of even small amounts of live phytoplankton in the diet of young animals ensures the rapid growth of fry and the improvement of their vital signs.

The diet of carp larvae, weighing up to fifty grams, consists of a special compound feed AK-1KE. Includes:

• Meat and bone meal.
• Yeast.
• Soya.
• Vegetable oil.
• Multivitamin Blend
• Dicalcium phosphate.

When a carp fry reaches a weight of fifty grams or more, it is transferred to AK-2KE compound feed. And when gaining weight from two hundred grams - feed RGM - 2KE. All compound feeds for carp fry include dry mixes of natural origin.

Daily allowance for carp fry weighing up to twenty grams is evenly distributed and given every hour during daylight hours. When juvenile carp gain weight fromtwenty grams or more, the number of feedings per day is reduced to nine to ten times.

Weight of young carp (g)	Degree of water heating (°С)	єС
Up to 3	25	30
3 to 5	15	20
From 5 to 10	11	17
10 to 20	8	14

In winter, if the water temperature remains 6°C and above, the fish continue to be fed, distributing the daily rate into three doses. In winter, feeding is carried out only in the daytime and in an amount sufficient to maintain metabolic processes. So:

• If the water temperature is 6-8°C - the norm of food per day is 0.5% of the weight of the fish.
• If 9-10°С - the norm is up to 1%.
• If 10-12 °С - the norm is up to 2%.

It is best to feed herbivorous fish in the winter with vegetable compound feed with a reduced protein content.

Planting of carp fry, the weight of which does not exceed twenty grams, is carried out with a density:

• For swimming pools 650 units per cubic meter.
• In cages - up to 500 units per cubic meter.

For young large fish species, this number does not exceed 250 individuals per cubic meter.

Fish Farm Business Plan

Fish farming is not a new business idea, but itrelevance today is only growing. The option of keeping your own bet or pond is a profitable business. But at the initial stage, it requires a solid investment and competent organization of the process.

First of all, it is worth finding a plot of land suitable for installing a pool with cages. A prerequisite for successful fish production is the availability of a special filter and equipment necessary for a particular breed of fish.

The purchase of young animals will also require significant financial costs. Keep in mind that the price of the larva is higher than the grown individuals. It is also necessary to calculate the natural losses of fry during the growing process. On average, this amount is up to 10%. It will be possible to grow a full-fledged adult from a fry only after two to two and a half years.

Any business project starts with a business plan. Evaluation of the fish market makes it possible to conclude that carp is the most popular product on the fish counters.

Indicative estimate for organizing a carp fish farm:

• Purchase of carp fry for replanting in cages - about ten thousand rubles;
• The salary of the farm employees is thirty thousand rubles;
• Batch of feed for carp larvae and vitamin mixture - seven to eight thousand rubles;
• Other expenses (payment for the consumption of water, electricity, gas for heating the pool) - twenty to twenty-five thousand rubles.

Total, the approximate amount that you need to have to start a fish farm is about seventy thousand innational currency. Therefore, a fish farm belongs to a business with an investment category of up to one hundred thousand rubles. For the northern regions of Russia, this amount increases many times, and amounts to approximately five hundred thousand.

As for profit, without deducting taxes and fees, it ranges from one hundred and thirty to one hundred and fifty rubles. However, you can count on profit not earlier than in two or two and a half years. By this time, the carp fry turns into an adult and its mass is one to two kilograms.

Carp, like no other species, is suitable for organizing a fish farming business. This is due to its unpretentiousness in food and maintenance. And the fast growing carp fry will help to quickly recoup the costs and get income. However, it is not worth neglecting the quality of the conditions for keeping fish and feed. The consumer attitude can lead to the development of pathologies in the fry and its death, as well as the discrepancy between the meat of adult carps and sanitary standards.

Pros and cons of the fishing business

If we analyze the successful experience of fish farming, we can highlight the following advantages in favor of this direction of agriculture:

• A small start-up capital makes it easy to set up a fish farm.
• The unpretentiousness of herbivorous fish in maintenance and care reduces the cost of the owner to pay employees.
• The rapid growth of fish of the cyprinid family (in just one year, the carp larva is gaining marketable weight of an adult) allows you to quickly recoup costs and make a profit.
• Unpretentiousness of cyprinids in nutrition. ExceptBecause they feed on their own, these fish give a good increase in weight and height when using any compound feed (both special, for fish, and for birds or cattle).
• Possibility of feeding carps with natural products - grain or potatoes (the only thing is that for better digestibility they need to be boiled beforehand).

Of course, there is a fly in the ointment in every barrel of honey. Running a herbivore fish business has its pitfalls:

• Seasonality of product sales. Basically, the fry is gaining commercial weight by autumn, and the massive supply of fish to the commodity counters, respectively, leads to a price decrease.
• During the summer, the transportation and storage of fish is a very costly and complex undertaking.
• The growth of fish is also directly dependent on the time of year: in the warm season, carp actively feed and grow rapidly, in the cold these figures decrease;
• Not every outlet can afford to purchase equipment for keeping the fish they sell.
• A separate item of expenditure falls on the maintenance of sanitary standards, the treatment of fish and their protection (we have many who want to go on "free fishing").

To get additional profit on a fish farm, it is necessary to take into account the natural symbiosis of the cultivated polyculture. There is an option to breed crayfish in the same area as carps. Go with other types of herbivorous fish. Lake crayfish not only perfectly clean the bottom of the reservoir (pond, cages), but also themselvesare competing products. You don't need to feed the crayfish. They feed on the remains of fish food and eat phytoplankton. During the molting period, crayfish become weak, some of them die, becoming food for fish.

It is possible to breed carp larvae for sale. For the maintenance of such fry, a separate water area will be required. However, such additional income is not immediately possible: male carps reach sexual maturity by the third year of life, and females only by the fifth.

Israeli experience

In the middle of the sands of the Negev desert in Israel, a fish farm has appeared. The distance to the nearest reservoir is about three hundred kilometers, while the density of farmed fish per cubic meter of water is about one hundred kilograms.

To create the water space of the farm, it took a well about a kilometer deep, from where water comes, whose chemical composition corresponds to that of the sea or ocean. This allowed the owners to start and successfully reproduce small marine fish.

Of course, the life support of the desert farm fish is in the hands of the staff of a special laboratory. They monitor the composition of water, the operation of fans, the purification and distillation of water and its saturation with oxygen. In addition, the life of fish also depends on uninterrupted electricity.

The creation of such a fish farm is not just a breakthrough in the development of the desert. Such a fish enterprise creates jobs and an alternative to catching fish in the sea.