Growing tench in ponds and aquaculture

 

Growing tench in a pond has been practiced for a long time. Tench has tasty meat, and tench also has a number of other valuable qualities that make it attractive for breeding. In this article we will look at how tench is raised in a pond, what tench eat and much other useful information for the farmer.

Content

• Tench fish description
• Tench fish in aquaculture
• What does tench fish look like?
• Where does the tench fish live?
• How tench grows
• Breeding tench in a pond at the dacha
• Breeding tench in a pond - how to prepare tench breeders
• Tench breeding in a pond - Tench spawning
• Tench breeding in a pond - Stimulating tench spawning
• Development of tench larvae
• Raising tench fingerlings
• Tench feeding young of the year
• Raising tench to commercial fish
• Growing tench in ponds in polyculture
• Catching reared tench in a pond
• Transporting tench

 

 

 

Tench fish description

Tench fish in aquaculture

Tench is a relatively heat-loving bottom fish. Tench lives in Asia Minor, in Siberia, up to the Yenisei, in the Caucasus and throughout Europe; tench does not live in the Scandinavian countries and on the Kola Peninsula.

Tench fish is a forgotten fish for fish farming, although previously in Rus' tench was grown together with carp and crucian carp and lived in almost all fish ponds. The popularity of the fish was ensured by its taste; tench meat is still liked by gourmets. Fried tench is especially famous. Tench liver has long been used to treat fever and headaches. There is a well-known saying in Ukraine: nothing is more beautiful than pork, and fish is more beautiful than linina. Tench meat tastes sweetish and very juicy, with medium fat content (3.8%).
One of the advantages of growing tench in ponds is the ability of tench, unlike traditional carp and other cyprinid fish, not to suffer from rubella, it does not suffer from dactylogyrus, it is not affected by other parasites that affect other fish. Tench can be grown in water bodies where many other pond fish simply cannot survive. Tench lives in reservoirs that are completely overgrown with algae; tench lives in reservoirs where oxygen deficiency is possible - below 1 mg/l. Tench lives in the most silty or peaty areas of the reservoir, where even carp cannot stay for long. Therefore, it is possible to breed tench in a pond at the dacha.

Due to the undemanding nature of tench, it can be grown over a large area, in different climatic conditions, as well as in reservoirs that are not suitable for other fish, for example in peat quarries.

In recent years, growing tench in pools, aquariums, trays and industrial installations with closed water exchange has become widespread.

Tench fish also has the advantage of ease of transportation to the consumer.
Tench are artificially bred in ponds with warm water, where tench are grown to obtain fish seed material, which is subsequently used to stock small lakes or reservoirs with fish: here tench live at significant depths, which are avoided by other fish species.

What does tench fish look like?

How to recognize a tench, what does a tench look like? Tench is easy to recognize by its appearance. This name was given to the fish for the characteristic feature of tench changing its color after being caught. A caught tench immediately becomes covered with large black spots. This happens because the fish is covered with a thick layer of transparent and extremely thick mucus, the mucus in the air begins to harden, darkens, and then it begins to fall off in pieces, leaving large yellow spots in these places.

What does tench look like based on body shape? The tench's body is spindle-shaped, short, slightly compressed from the sides, thick and not high. Depending on the sex, the tench's body shape may vary: male tench have a larger head, and the front of the back is narrower and higher than that of female tench. The tench's body shape is influenced by its environment. The tench living in the lake is wider and higher in the dorsal part, and therefore, having the same length, is heavier than the tench living in the pond. But if a tench from a pond is placed in a lake, the fish change their body shape. The tench living in the lake is similar: in the pond, the fish takes the form of a tench from the pond.

What tench looks like based on color. As a rule, in the description, tench has an olive green color. But it is not always possible to identify what a tench looks like by its standard color. Sometimes it is of a different color - as an option there is a “golden tench”, such fish do not have black pigment cells, but are more yellow and red, in addition, there is more guanine. There are also black lines, but they are extremely rare. Tenches lack red and yellow pigments. Very rare albino tenches are fish with red eyes. A tench is described with a bluish belly; such fish lack a silvery sheen.

The caudal stem is short, with a small notch. All tench fins are rounded. The dorsal fin of the tench begins slightly behind the vertical of the posterior edge of the base of the ventral fins or above them. The pectoral fins are long. The scales are very soft, which fit tightly to the body; the scales are very difficult to peel off. Usually The tench's body is covered with mucus, especially at low water temperatures. The head of the tench is small, the snout is blunt, the mouth is small and terminal. There are short antennae at the corners of the mouth. The eyes are small, the forehead is wide and flat. The pharyngeal teeth are single-rowed.

What does a tench look like, is it possible to distinguish a male from a female? The secondary sexual characteristics of tench are described as follows. Male and female tench can differ both in body shape and in secondary sexual characteristics: the male's pelvic fins are larger, spoon-shaped, and the males have a powerful second hard ray, slightly curved outward. The pelvic girdle and muscles at the base of the fins are more developed in males than in females. These sex differences can be observed as early as the second year, at which time it is possible, although not very accurate, to separate fish by sex.

Where does the tench fish live?

Where does tench live? Tench is a sedentary fish and does not make large migrations. The fertility of tench reaches 1 million eggs. Tench spawn in May-July at a temperature of 20-25°C in portions. In natural reservoirs it grows slowly.

So where does tench live? Where does tench live in a river or pond? Tench preferably lives in quiet, grassy, moderately silted reservoirs with soft underwater vegetation, where it hides in the thickets during the day. Here the fish finds food for itself, and also consumes the remains of food that has fallen to the bottom of the reservoir, thereby preventing its decomposition and thereby improving the sanitary condition of the reservoir. When tench and carp are grown together, the carp mainly stays in the open part of the reservoir and consumes the food there; in search of food, the carp explores the deeper layers of silt. This makes it possible to more fully use the natural food resource of the reservoir when growing tench and carp together.

Where does tench live in winter? In winter, tench burrow into the mud and hibernate.

Oxygen consumption by tench. The oxygen consumption of tench is insignificant: at the same temperature, per 1 kg of fish weight in 1 hour, fingerlings consume 103 cm 3, i.e. 157.1 mg, two-year-olds - 69 cm 3, or 98.6 mg, and three-year-olds - 50 cm 3, or 71.4 mg of oxygen. Tench consumes less oxygen than carp or trout. Thus, for every 10 cm 3 of body surface at a temperature of 15 ° C, tench consumes 44 cm 3 in 1 hour, and carp under similar conditions consumes 110 cm 3, trout - 264 cm 3 of oxygen. Oxygen consumption in tench, like in carp, depends on temperature. For example, a tench weighing 1 kg at a temperature of 0 ° C consumes 6.05 cm 3, or 8.64 mg, and at a temperature of 25.1 ° C during the same time - 100.34 cm 3, or 143.34 mg of oxygen.

Temperature limits. Tench can tolerate a significant increase in water temperature - up to 37° C. But at a water temperature of 23.5° C, the fish already begins to experience thermal torpor, and when the temperature drops to 4° C, it goes into hibernation.

pH value range. The permissible pH range for tench is from 5.5 to 9. The fatal pH value for tench is 5-4.5 and 10.8, it is identical to similar indicators for carp, but tench tolerates a sudden change in pH value more easily than carp and other species fish However, fish are more sensitive to mechanical stress.

 

 

 

How tench grows

 

Tench grows relatively slowly. The growth of tench depends on the living conditions of the fish, gender, and heredity. For this reason, tench does not grow well in every body of water. In particular, regular liming of ponds can negatively affect the growth of tench. A good habitat for tench are bodies of water with soft soil, overgrown with underwater vegetation and plants with floating leaves.

Female tench are larger than males, female tench grow on average 30-40% faster.

As a rule, tench fingerlings reach a weight of 10-15 g, two-year-olds - 150-200, three-year-olds - 300-350 g. If yearlings have reached the maximum achievable weight of 25-45 g, then in the 2nd year of life the fish can reach a marketable weight of 180 -200 g. Otherwise, growing tench lasts for three years, then the tench reaches a weight of 380-400 g. In the south of Russia, fish can reach this weight already in the 2nd year, and in the third year reach a weight of 800-900 g.

Table Linear growth of tench in natural reservoirs

Age, years	1+	2+	3+	4+	5+	6+	7+
Length, cm	3-7	6-12	11-17	15-23	17-26	20-29	25-32

 

Who grows faster, tench or crucian carp? Farmers are often faced with the question of what fish to breed and compare different types of fish. The most unpretentious fish that can be raised in a pond at the dacha are tench and crucian carp, which is why the question arises: who grows faster, tench or crucian carp. It should be noted that tench grows slower than silver crucian carp; golden crucian carp grows at the level of tench.

Breeding tench in a pond at the dacha

Breeding tench in a pond - how to prepare tench breeders

The easiest way to get offspring from a tench is described by Ukrainian scientists. In Ukraine, female tench mature in the 3-4th year, males - in the 2-3rd year, in the Moscow region and other more northern regions - 1-2 years later. Male tench become sexually mature already at a length of 11-20 cm, and females - 18-20 cm and an average weight of 100 - 120 g, tench fertility is 20-40 thousand eggs, female tench weighing 0.5 kg produces approximately 300 thousand eggs; in large specimens weighing 0.8-1 kg, the fecundity of tench reaches up to 500 thousand eggs.
Typically, tench producers are harvested in the spring at a temperature of 10-16°C; The sex ratio of tench producers is as follows - 2-3 males are needed for one female. Male tench develop a pearly rash during spawning, which goes away after spawning.
Tench breeding in a pond - Tench spawning

Before planting tench for spawning, the spawning pond is prepared: ditches are cleaned, the bottom of the pond is loosened with a rake, liming is carried out, and fertilized with superphosphate and ammonium nitrate.

When does tench spawn? In mid-latitudes it is a typical summer-spawning fish. Tench spawning occurs from May to August, but in cold years, tench spawning lasts until September.

Tench spawning begins when the water warms up to 20° C in the absence of wind and in stuffy weather. Tench spawns somewhat later than carp.

During the spawning period, tench enter shallow water areas; females lay eggs in three or more portions. After the first portion of eggs, the female can lay the second portion in 6-10 days; after about the same interval, another 2-3 clutches of eggs can occur. The eggs are very sticky and adhere well to aquatic plants. Unfertilized eggs live no more than 2 minutes. The sperm loses its mobility in water within a minute. Therefore, tench eggs must be fertilized within 1 minute. Without water, eggs and milt remain viable much longer, so there is no difficulty in artificially fertilizing tench eggs. Eggs are taken from female tench during the period of greatest maturity, which occurs during spawning.

Tench spawning occurs quietly and unnoticed. Tench spawn in small groups - one female and two or three males. Tench spawning continues for a long time: the smallest individuals spawn first, and then the larger individuals.
Tench can spawn in small and shallow bays or ponds, up to 30-50 cm deep. Macrophytes with submerged leaves (pondweed, urut, etc.) serve as a substrate for sticky eggs of tench. But in their absence, spawning can also be carried out on artificial nests, made from a nylon washcloth or old cloth, which are attached to a hoop with threads. When breeding tench in homestead ponds, in the absence of algae, they can be added in bunches for the spawning period, caught from the nearest swamp.
In Western Europe, pituitary injections are widely used to produce offspring. In Poland, tench larvae are obtained in this way for export. For this purpose, tench spawners are kept either in ponds or in flowing gutters, as is done in fish farms in the Czech Republic and Slovakia, where spawners are planted at a stocking density of 50 pcs/m3. Working fertility -100 thousand pieces. per 1 kg of female.

Tench breeding in a pond - Stimulating tench spawning

Producers are injected at the following rate: for females - 10-20% of the volume of carp pituitary gland suspension (preliminary) and after 12-24 hours - a resolving injection, a total of 15 mg per 1 kg of average weight. Males are injected once - only 3-5 mg per 1 kg of body weight. At a temperature of 21-24°C, ripening occurs 22-26 hours after the permissive injection. If the temperature drops below 20 C, ovulation of eggs may not occur. Injected spawners can be left in the pond, but in these conditions the fish are already out of control, so the eggs may be released and remain unfertilized.
Typically, 100 ml of caviar requires 0.3-0.5 ml of milt from different males. Talc and milk are used to destick caviar. Incubation is carried out in Weiss apparatus, into which 1 liter of caviar is placed, containing 0.7 million eggs.
If there are no Weiss devices, fertilized but not deglued eggs can be placed on an artificial substrate for incubation in a pond, and for better aeration, the substrate with eggs can be installed in an area of water supply or intensive water exchange.
The larvae hatch after 75 hours at an average temperature of 2°C; at a higher temperature (22 C), embryos develop in 70 hours.

Development of tench larvae

Development of tench larvae. Hatched tench larvae, 3.5-3.6 mm long, attach to the substrate, feed on the reserves of the yolk sac for 3-4 days, growing during this time to 4.5-4.7 mm and concentrating in shallow water, where they actively feed on unicellular algae and small zooplankton. If there are a lot of larvae, they are fed with small zooplankton filtered through gas ╧ 17-19. At a length of 6.5 mm, the larvae begin to consume larger organisms, spreading throughout the entire pond. Already when they reach a length of 1.3 cm, the fry feed, in addition to plankton, on bottom organisms. The most favorable temperature range for growth is 20-29°C; when it drops to 10°C, the fish stops feeding, and at 4°C it buries itself in the silt and goes into suspended animation. Upon reaching a length of 1-2 cm, the fish must be seated at such a density that there is enough food.

Raising tench fingerlings

Growing tench fingerlings. In Ukraine, in ponds measuring 500 m2, 10 thousand fingerlings with an average weight of 12 g were obtained from one female weighing 0.9 kg with the participation of 2 males. When obtaining larger fingerlings, the rearing density is reduced to 5-6 thousand pcs/ha and even to 600 pcs. (without further feeding and without replanting for wintering). With such a density of fish stocking, the mass of tench from fry of 1-2 g can reach 25-45 g.

Tench feeding young of the year

Tench fingerlings feed on worms, large crustaceans, small mollusks, chironomid larvae, and plant remains, but prefer detritus. If, due to the high stocking density of the tench, there is not enough natural food, it is necessary to feed the tench with artificial food. To do this, a feeder is installed on the pond, into which various feeds are added - grain waste, mixed feed, weed seeds, as well as fresh vegetables (beets, carrots, potatoes) minced through a meat grinder. You can give finely chopped pondweed, cabbage, etc.

Favorable vegetation for breeding tench are water buttercup, telores, hornwort, pondweed, urut and elodea.

Tench feed on the same artificial food as carp, but it should be smaller, because tench have a different structure of pharyngeal teeth.

Raising tench to commercial fish

Growing tench to commercial fish.
When growing tench in two- and three-year-old ponds on natural food, a tench stocking density of 250-600 pcs/ha is recommended. When feeding, tench stocking density can be increased by 5-10 times. In this case, like fingerlings, tench are fed chopped vegetables, potatoes, mixed feed, and grain waste at feeding areas. The fish productivity of tench can be 1-2 c/ha without feeding and 6-8 c/ha with feeding.

Growing tench in ponds in polyculture

When raising fry in a polyculture with silver carp in Germany, dry feed was effectively used. Tench eats significantly less feed than carp, silver carp, and grass carp. For 1 kg of gain, only 2.5 kg of feed was required. When growing in polyculture with carp, it is recommended to use overgrown and silted ponds. Tench colonize biotopes where carp are rare, which makes it possible to effectively use the natural food reserves of the pond.

In a polyculture with carp, marketable tench is 1-2 c/ha with a total productivity of 15 c/ha.

It is advisable to grow tench in polyculture as an additional fish, adding it to carp, whitefish, and trout.

Also, several tench nests can be placed in a pond where pike perch is raised; the tench fry in this case are food for the pike perch.

Catching reared tench in a pond

In small ponds there is no problem with catching tench. Fish concentrate in feeding areas and are easily caught by dragnets. Larger ponds should be drained quietly at night, otherwise the tench may burrow into the mud and remain there even after all the water has gone. To concentrate fish on the pond bed, a reclamation network and a recessed area (the so-called fish collection pit in front of the discharge device - “monk”) are needed.

When catching fingerlings in the fall, you need to take into account one feature of tench: when the water temperature is below 10 degrees, it buries itself in the silt. In view of this, it is necessary to drain ponds in the fall at a temperature of at least 10 degrees. When draining the water, it is necessary to check whether the fish remain in any recesses.
Transporting tench

Tench is easy to transport over long distances even without water, in a humid atmosphere, where it can live for 5-6 hours. But it should be remembered that it is very sensitive to mechanical damage and must be handled very carefully.