Hello my beloved ones of @farms play for Tuesday a special challenge like fish and I want to talk to them how to grow them and how we want to set up a catfish farm.

The South American catfish develops well in waters with temperatures close to 20 °
C, reaching 400 g of weight in about six to seven months. When being raised under systems
intensive in ponds on land, this species can yield beneficial productions of
order of 1,500 to 1,800 kg / ha / year. When using cages suspended in bodies of water
suitable for these crops, the production can reach 90 kg / m3

A person interested in the cultivation of catfish must decide, in accordance with their
own economic possibilities, the type of fish farm you want to establish,
considering the level of production you plan to obtain, the availability of capital
investment and a correct water supply. The plan of a fish farm should be
done with extreme care, since it is the most important part for a good operation.

large sea catfish

1. TYPES OF CROPS

1.1 CROPS IN PONDES ON EARTH

The crops developed in ponds are the most classic in the production of
this one and other fish. These ponds are excavated on land, and their number, shape and size
are determined both by the planned production, and by the type of soil, the
topography of the land and the availability of water supply.
The size of the ponds can be varied. For fish farmers that start, they
advise a size that does not exceed one hectare, with the initial fish farm a total
of four hectares at most. The soil where the ponds are built must be of
land that can hold water well, in order to have no extra cost in sealing the
same. The best lands are those called "black lands", with abundant
Acceptable cohesion clay ratio.

A fish farm needs a water distribution system and a drainage system;
effective protection against floods; and a network of roads that allows transit
of a vehicle between the ponds. The size and design of the pond is so important,
as the entry and exit of water.
The piscigranjas must be located in soils that do not receive water drains
with pesticides of any kind and the water supply must be free of
contamination. In case of doubt, it is advisable to previously carry out water analysis.
The best ponds to save space and work are the rectangular ones,
that share slopes, with independent water supply and drainage. Each
pond constitutes a management unit. The major axis of the pond should be oriented
parallel to the prevailing wind during the summer, in order to contribute to
oxygenate the culture water.

1.2 CULTIVATIONS IN CAGES

The cages constitute only a part of the total of a fish farm. They can be
Constructed in plastic mesh fabric, in nylon or galvanized wire, resistant to
corrosion. The frames of the cages that are rigid type, can be manufactured
in treated wood or metal. The cages have an upper closure or lid, which is used in
the partial or total extraction of the fish.
The daily food is supplied without opening the lid, through the mesh of the same.
The total harvest of the fish can be done in the place where the cage is installed, or this
can be towed from a boat, gently, to the shore of the body of water,
where it will proceed comfortably to make the total harvest. The cage also
It can be raised over the edge of the boat and its lid open to observe or extract the fish.
The suspended cages float by means of small fuel drums,
hermetically sealed; It can also be done by means of blocks of pagopor. For
1 m3 cages
It is enough drums of four liters.

2. KEY FACTORS IN THE CONSTRUCTION OF A FARM
SWIMMING POOL WITH PONDS ON EARTH

2.1 WATER SUPPLY

The good quality of the water and its availability is the key factor in the determination
of the installation and operation of a fish farm. The best water is that which comes from
wells, since it avoids the possibility of introduction of unwanted fish, diseases,
pesticides, very muddy waters and floods. The disadvantages are its lower temperature,
its greater hardness, its lack of oxygen and its high transparency. The water flow of a well
determine the production of fish on a farm.
A pond, in semi-intensive culture will need approximately 12
liters / second / hectare. As indicated above, this crop produces in "fattening"
between 1,500 and 1,800 kg / ha / year. The water supply will be necessary not only for
proceed to the initial filling of the ponds, but to replace the losses by
evaporation or seepage of the soil, as well as for the maintenance of a good quality
(in dissolved oxygen, especially) during the culture operation.
The waters from wells lack oxygen. Therefore, they should

2.2 QUALITY OF CULTIVATION WATER

The water of culture includes factors of diverse types: biological, physical and chemical.
Maintaining the good quality of it is vital for the life of the fish in breeding and for success
of the cultivation that takes place; At the same time, it is important for the achievement of older
productions
In order to determine the quality of the water supply of a
piscigranja can be resorted to with the help of specialized institutions, to carry out
the corresponding analyzes. The fundamental characteristics to determine for your
Use in fish culture are: pH (water acidity), total hardness (amount of
carbonates), amount of oxygen in solution and temperature (winter and summer). Further,
the presence of elements harmful to the life of the fish, such as
iron, arsenic and lead, and excess of other heavy metals.
The pH of a water should vary between 6.5 and 8.5. If the pH is less than 7 and the alkalinity
total is less than 10 ppm, it can be leveled by successive whitewashing
with lime for agricultural use, after having carried out a previous analysis of the soil of the
pond. Low pH values ​​produce water-soluble ammonia, which is very harmful
for the fish.

3 OPERATION OF A PISCIGRANJA</h1

3.1 DESOVE OF THE SOUTH AMERICAN BAGRE

For small and initial commercial farming operations, the fish farmer may
buy the larvae of this fish for sowing in their ponds to a State Center that
cultivate These larvae can be newborns (4 mm), or they can be 1.5 cm, with 15
days of life
However, given that this type of crop has just started in Argentina and is not
possible still to have enough "seed" batches produced by others
fish farmers or by the State itself, in cases of major operations will be necessary
that the same fish farmer proceeds to obtain his own seed, which he will raise in his ponds
up to the desired size.
The necessary infrastructure for a farmer who wants to produce a large number
of these fish in juvenile size, includes ponds intended for stabling
reproducers, suitably conditioned and at the same time suitable
to carry out the incubation of the eggs, as well as the breeding of the small larvae
new born.

Every few years, new players should be selected to replace the
first, as a way to renew the stock. The producer must avoid making crosses
consanguineous You can avoid this fact if you have several lots born of different parents or
if it mixes again with wild reproducers, in the case of lack of suitable material.
Each time the farmer introduces animals from the natural environment into his
farm, you must take great care to set them aside previously and carry out a quarantine,
keeping them in good physical condition until finally passing them to a common stock.
Preventing in this way, will avoid introducing diseases transmitted by animals of the
natural environment Reproducers from different environments or from different years (when
deals with own stock) may be marked for quick identification. It is useful to control
the predetermined marks that are applied to them.
When the water temperature reaches around 21 to 22 ° C, the
reproducers may be paired to effect controlled reproduction; is
convenient that this temperature is stabilized.
In order to carry out an artificial reproduction, it is important to use
hormones to accelerate the maturation process. The most common is the so-called
Human Chorionic Gonadotropin (HCG), for medicinal use, which can be used in Argentina
Acquire current in pharmacies; example: Endocorión, of laboratories ELEA, that
It has 5,000 International Units (UI). The boxes are sold with distilled water or
another solvent and a small accompanying bottle that has the hormone powder, which
It must be dissolved in the same bottle, adding the solvent.
For greater security, once the pairs are formed, the three female is injected
dose of 1.5 IU / kg of weight, with an interval of 24-48 hours. To the male fish, whose
maturation is confirmed by mild abdominal pressure (ejects white semen), it is injected
a single dose that, in general, accompanies the third dose of the female. The applied dose
The male is 0.7 IU / kg of animal weight. If it were observed that the female is very
mature, you can accompany the first injection for her with one to the male, in order to
return more fluid to the semen of the animal and that greater fertilization of eggs occurs. TO
Below is an example of a dose calculation:

Example:

Calculation of the dose of hormone to be injected into a female weighing 1,500 grams
and to a male of 1,200 g, using GCH (Endocorión), of 5,000 IU. As the total dose is
should divide in three injections, the female should be injected in each dose 770 IU.
Dosage for female.

500 g ..................... .. 770 IU
1,500 g ..................... 2,310 IU
Dosage for the male
500 g ........................ 400 IU
1,200 g ...................... 960 IU

Then calculate how many milliliters (ml) of solution
it will correspond to apply in each case. We said that the solution is 5,000 IU, dissolved in 5
ml. Thus:

For females
5,000 IU .................. .. 5 ml
700 IU ..................... 0.77 ml per injection
For males
5,000 IU ............... .. 5 ml
960 IU ................ 0.96 ml in one injection

It is convenient that couples are mature for their reproduction and are of sizes
similar. The health status of the chosen specimens must be optimal; they should never be used
specimens that present bad conditions, deficiencies or malformations in the body. Should be
avoid injured individuals, with parasitism, abscesses or other diseases, since in the
Most of these cases can be transmitted to offspring.*

3.2 HANDLING OF EGGS. INCUBATION AND OBTAINING LARVAE

With the intention of removing the fertilized eggs from the containers, the flow of
water by filtering through a fine mesh of 1 mm, placed in a wooden frame. The
Already removed eggs are passed in successive litters to incubators.

The incubators can be built in plastic and must have an entrance and
independent water outlet. The litter of eggs to be incubated depends on the size of the
incubator to use. If it is a cup-shaped, the eggs inside must
be agitated with smooth and continuous movement, which prevents its exit by overflowing.
The water inlet rod
must have a diameter of about 3 to
4 mm Its filling must be effected
slowly to overflow the
water by the exit and regular to
then the flow of it. He
set of eggs in incubation not
must exceed half the bottle or
incubation cup. If I dont know
produce abnormalities, duration
from the incubation process until the
birth of small larvae
will be related to temperature
water environment used. By
example, at room temperature
constant of 27 ° C, the birth of
the larvae will occur in
approximately 36 hours.

obtaining larva

egg incubation

egg handling

4. CRY OF LARVAS UNDER ROOF

In the same house where the spawning occurred and the incubation was carried out,
will have an adequate number of tubs for breeding and nursery of newborn larvae
Approximately 200 larvae / liter can be grown. The density of larvae in breeding
depends on the amount of water flow that can be kept in the tub, and the amount
of dissolved oxygen to obtain an excellent quality of water. By the type of larvae
that has this species at birth, the use of suspended baskets is recommended
in vats as described. The larvae measure about 5 μm and, if you want to increase the flow
of water in the tub to increase its density, the problem arises that larvae
they would be dragged by the force of the current and they would be trapped in the mesh of
retention, before the water outlet.

4.1 YOUTH PRODUCTION IN OUTDOOR POOLS

As stated above, after 11 days of feeding the larvae continue
They measure an average of 1.5 cm in total length. Since the range is variable within a
same crop (can reach from 1.0 to 3.0 cm), three are usually selected
Sizes for planting in ponds: small, medium and large. How much more
uniform be the size at the time of planting, more homogeneous will be its growth
until reaching the size of juvenile suitable for fattening.
The ponds that will be used for breeding of small juveniles of 15 days of
life until large juveniles of 16 cm or more, should be prepared to receive them. It
is extremely important and can be a critical phase of cultivation, in which the good
growth of the planted juveniles is concerned. The best preparation method is that
that prevents the spread of insects and that, at the same time, offers a natural food
in optimal quantity so that small fish grow quickly.

5. SELECTION OF PLAYERS

Juveniles of good growth can be selected at the time of
harvested and brought to fattening to be used as future broodstock in ponds
appropriate. The adequate density will be 3,000 individuals / ha (0.3 / m2)
); this way a
own stock of reproducers.
The size of the males is smaller than that of the females of the same age. For this
motive it will be advisable to select minor specimens when making the selection
size, since the largest ones may turn out to be only females. After a few months of
growth can be selected again.

It will be necessary for the producer to also select children of different parents, who
have had good growth. If they were all brothers to each other, you would get
reduction in size due to consanguinity. In contrast, when interbreeding batches of males
and females, better growths will be obtained.

The great harvest of the catfish already raised and cultivated*

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