Growing zander in ponds and intensive aquaculture
Breeding zander fish in aquaculture zander - Stizostedion (Lucioperca) lucioperca - is highly valued for its tasty meat.
zander is a valuable commercial fish, which is often grown in polyculture, together with carp and other fish; zander is a biological ameliorator, therefore it is often used for pasture fish farming. Due to the high growth rate of zander, it is widely used in industrial aquaculture, where zander are raised in cages. Recently, breeding zander in RAS has become widespread.
Content
- Growing zander as an aquaculture object
- Zander as an aquaculture object
- Description of zander fish
- Where does zander live?
- Nutritional value of zander
- Growth of zander - how zander grows
- Spawning zander or breeding zander in a pond
- How quickly does zander grow before maturity?
- Zander spawning period
- Zander food
- Are zander raised artificially?
- Growing zander in artificial conditions - obtaining offspring
- Growing zander in artificial conditions - raising fry
- Growing zander in artificial conditions - wintering zander
- Growing zander in artificial conditions - obtaining marketable zander
- Some features of growing zander in ponds
Growing zander as an aquaculture object
Zander as an aquaculture object
Zander is a valuable fish that has valuable and tasty meat and is in great demand among the population. The growth of zander is fast; zander can be grown in polyculture with other fish species. zander is often grown in reservoirs as a monoculture. zander is a good bioreclamator that eats low-value and trash fish - ruffe, perch, goby, bleak, verkhovka and others. The ameliorative effect of zander in a reservoir is estimated by consuming 3–5 kg of trash fish per 1 kg of weight gain of zander. At the same time, valuable fish species, among them such as carp, bream, crucian carp, peled, due to their high back, quickly become inaccessible to zander, which is why zander compares favorably with pike. In polyculture, zander can only eat individuals that are lagging behind in development. Breeding zander allows you to remove trash fish from the reservoir, make more complete use of the reservoir's food supply and obtain additional high-value fish products.
zander is often used for pasture fish farming, to form a useful ichthyocenosis of the reservoir. Walleye are widely farmed in industrial aquaculture, where walleye are raised in cages. In recent years, growing zander in RAS has become widespread.
All these qualities make zander a valuable object in aquaculture from the southern regions to the north-west of Russia.
Reproduction and rearing of zander in cages
Breeding zander (Stizostedion lucioperca) in fish ponds
Spawning of zander in artificial ponds
Description of zander fish
zander is a valuable fish with a low, slender body that is laterally compressed. The dorsal fins touch or are separated by a small gap. Often the spiny spines of the fin are hidden under the skin. The head of a zander is easily recognized by its elongated jaws, the head smoothly transitions to the back. The body of the zander is colored greenish-gray, the belly of the zander is light, and on the sides of the zander there are 8 - 12 vertical stripes of dark color. The caudal fin and dorsal fins have rows of dark spots, the remaining fins are pale yellow. The mouth of the zander is large, the upper jaw extends beyond the rear edge of the eye. The jaws and palatal bones are strewn with numerous teeth, and there are also strong fangs. The cheeks of zander are bare or covered with scales only on top.
The life cycle of zander is greatly influenced by climate, so individuals from the northern regions have a long life cycle; in Lake Onega, individual fish reach the age of 17–20 years, but in most cases fish from 6 to 11 years predominate. Puberty of zander occurs no earlier than 7–8 years. However, as you move south, zander's life expectancy and puberty period are reduced. In the Volgograd Reservoir, zander reaches the age of 8 years. The life expectancy of zander in the Varnavinsky and Veselovsky reservoirs does not exceed seven years. Mass sexual maturity of zander in the south occurs at the age of three to four years.
Where does zander live?
zander is widely distributed in the basin of the Azov, Black, Caspian, Baltic and Aral Seas. zander is acclimatized in the White Sea basin, in Western Siberia, in the basin of the Irtysh and Ob rivers, as well as in the Amur River in the Far East. zander lives both in freshwater bodies of water - reservoirs, lakes, slow-flowing rivers, and in brackish water bodies - estuaries, desalinated areas of the seas. A semi-anadromous form of zander, it feeds in desalinated shallow areas of the sea with a salinity of 7–9 o/oo, and enters estuaries and rivers to spawn. zander is not found in swampy bodies of water, as it is very sensitive to the oxygen content in the water (up to 13%). zander tolerates water pollution very poorly and, when toxic substances enter it, dies earlier than most other freshwater fish.
zander obimelts in the pelagic zone, in which it stays at different depths, which depends on the location of its main food and water temperature. Only juvenile zander live in the littoral zone during the first year of life; mass approach of adult zander
littoral zone is observed only during the spawning period.
Nutritional value of zander
zander has excellent taste. zander is valued for its white, tender, tasty meat, although lean (1.1%), for the absence of intermuscular thymus bones. The nutritional value of zander is very high - the protein content in the meat reaches 18.4%. zander meat contains all 20 amino acids, 8 of which are essential, and also contains a number of minerals (potassium, calcium, phosphorus, chlorine, sulfur, sodium, iodine, magnesium, iron, zinc, copper, manganese, chromium, fluorine, cobalt , nickel, molybdenum) and vitamins (A, E, C, PP,
group B), which are necessary for the full functioning of the human body. This results in a high market price for zander.
Growth of zander - how zander grows
How does zander grow? The growth of zander, like the growth of other fish, is associated with a whole complex of environmental factors; at a young age, the growth of zander depends mainly on the concentration of crustaceans; at an older age, the growth of zander depends on the number and availability of the fish on which it feeds. How long does zander grow - in the lower reaches of the Southern Bug, the body length of a one-year-old zander is on average about 20 cm, seven-year-olds - 64 cm, in the lower reaches of the Dnieper, the body length of zander is 17 and 70 cm, respectively. In the southern reservoirs, the growth rate of zander is high, but in Chograi In the Veselovsky and Proletarsky reservoirs, the limiting factor for the growth of zander is sharp fluctuations in water salinity, and in the Shapsug reservoir, the limiting factor for the growth of zander is the low level of food supply.
How does zander grow over the years?
Zander, like many predators, grows quite quickly. Fingerlings gain weight of 100-150 g, two-year-olds - 500 g, in the 3rd year - 900 g, in the 4th - 2500 g with a length of 40 cm.
How much does zander grow in a year? In southern reservoirs, zander grows quickly. The weight of zander depending on the length - for fingerlings the length is 20 cm, average weight 80 g, for two-year-olds 30-35 cm and 500 g, for three-year-olds 40-45 cm and 1.1 kg, for four-year-olds 50 cm and 2 kg, for five-year-olds 50-60 cm and 3-3.5 kg.
How much weight does zander gain per year from larvae? Under favorable conditions, within a year, zander will reach a length of 20 cm and a weight of 70-80 grams, and can gain weight up to 100-150 grams.
In cold or poorly warmed waters, zander grows slowly.
Based on the data on how quickly zander grows, it can be noted that in two years a zander can grow up to 30 cm, the mass of a zander with a length of 30 cm is 500 grams, and how long a zander grows up to 1 kg is another year. Thus, in three years, when raising zander on pasture in a pond or other body of water, you can get marketable fish without compromising other species of fish.
Spawning zander or breeding zander in a pond
How quickly does zander grow before maturity?
At what age does zander mature for spawning? zander matures at the 3-4th year of life. The fertility of a female zander weighing 500 g is 150 thousand eggs.
zander have been acclimatized in various reservoirs in Europe and Asia, and there, harvesting spawners does not present any difficulties. There are several spawning and rearing farms in the Kuban, Don, Volga and Dnieper, where offspring from zander are obtained in a way suitable for obtaining planting material on a farm, for which they choose a pond where water exchange can be created and artificial nests for zander can be installed.
The maturation of zander occurs in water bodies of the cold zone at the 4-5th year of life, and in the warm zone - at the 2-3rd year of life. The age of maturation and fecundity of zander correlate with the length and weight of the fish. When selecting zander producers, you can rely on the following data:
Dependence of zander fertility on body length
Length, cm
Fertility, thousand eggs
30-40 100-150
41-50 200-300
51-60 400-500
61-70 600-800
61-70 600-800
Dependence of zander fertility on body weight
Average weight, kg
Fertility, thousand eggs
Up to 0.5 100-300
Up to 1 170-200
Before 1.5 250-300
Until 3 400-500
Up to 5 700-800
Zander spawning period
When does zander spawn? Pike-perch spawning takes place in the spring, but the beginning of pike-perch spawning depends on the region: in the northwest, pike-perch spawning takes place in May-June. Thus, spawning of zander in Lake Onega takes place at a water temperature of 15–16 °C in mid-June. In the Azov-Caspian region, zander spawning occurs in March-April. In the Sea of Azov, zander spawn from mid-April to early June at a temperature of 17–18 °C.
zander spawn once. The working fertility of a female zander reaches 175-200 thousand eggs, the diameter of fertilized eggs is 1.3-1.4 mm. Embryo development lasts 140 degree days. The least sensitive stage of development is the beginning of the motile embryo stage.
Zander food
zander larvae have a significant fat reserve, which is enough for 6-7 days before the start of external feeding. The size of the larvae at this time is 5.5-7.0 mm. The zander's requirement for a high oxygen content (at least 5 mg/l) limits its feeding areas. It is usually concentrated in areas of clean reaches and channels with clear water and is almost never found in shallow waters up to 0.5 m deep.
zander is highly flexible in its diet. The first food of juvenile zander is zooplankton, which it feeds on until it reaches a size of 10-13 mm. Fish larvae begin to be found in the food of juvenile zander after reaching a size of 30-40 mm. When raising fry, you need to know that for fish weighing 0.1-0.2 kg, 3 carp fry weighing 2-3 g are required. It is believed that the zander is provided with food if, upon opening a batch of fish, it is discovered that 30% of the stomachs were empty. The yield of fingerlings from hatched larvae is from 15 to 50%. The level of development of the food supply during this period is a determining factor in the survival of juvenile zander.
The food supply for adult zander is very diverse and zander food has a wide range. As a rule, the food of adult zander consists of small mass fish: in reservoirs of the north-west, zander eats vendace, smelt, smelt, perch; in the Volgograd or Saratov reservoirs, zander eats sprat, gobies; in the Veselovsky or Proletarsky reservoirs, zander eats roach, bleak, silver crucian carp, in the delta of the Kuban and Don rivers, the main food for zander is bleak, gobies, perch, and crucian carp.
The diet of zander is very varied and, as it grows, undergoes significant changes and is closely dependent on its size. Thus, studies of the feeding of zander in the Krasnodar reservoir have shown that zander larvae in the early stages of development consume rotifers, and with increasing size they switch to feeding on cladocerans and copepods. In general, zooplankton in zander fingerlings makes up 52.59% of the diet. As the zander grows, the food spectrum expands, and nektobenthic (gammarids and mysids), as well as benthos (chironomid larvae and other invertebrates) appear in the zander’s diet, which make up
respectively 22.28%, 10.75 and 10.36% of the diet. This is caused by the richness of the reservoir in zooplankton and higher crustaceans during the growing season.
The transition to feeding on young fish is usually carried out by zander at the end of summer or the next year.
In the second year of life, the role of fish in the diet of zander increases to 53.40%, but the importance of benthic organisms, especially mysids, is relatively high. At the age of three, zander practically stops feeding on invertebrates, mainly feeding on fish.
The species diversity of fish in the diet of zander depends on size. zander up to 10 cm in size (0+) feed on bleak, zander and bersh no larger than 1–2 cm in size.
As it grows, the species diversity and size of fish in the zander's diet increases. Two-year-old zander 20–25 cm long eat roach, perch, sabrefish, zander, and bersh, but the main diet of zander is bleak (45.16%). From the age of three, bleak accounts for 66.54% of zander’s food, although zander eat 10 species of fish: carp, bream, silver crucian carp, saberfish, roach, bleak, bersh, zander, perch, river goby and sandpiper goby, Caucasian river goby.
zander aged 3+ is a typical predator that feeds on fish living both in the pelagic zone and in the coastal zone. Depending on the age of the zander, the length of the fish it feeds on ranges from 1 to 15 cm, but on average it is 5–7 cm.
zander begins to feed in March when the water temperature is above 5 ºС. The greatest feeding activity of zander is observed in June-July. At this time, zander consumes more than half of the annual diet - 52.05%; from August the feeding intensity decreases.
On average for the population, the feeding coefficient of zander is 9.1 units. The minimum feed ratio for zander fingerlings is 6.8.
Standards for commercial cultivation of zander on the Lower Don
Manufacturers length, cm more than 3.3
water t when selecting producers, °C 5-6
Planting density of manufacturers in the slot, pcs/m3 150
Density of nest placement when rearing zander, pcs/ha
in monoculture 4-5
in polyculture with carp 2
Flow during the spawning period, m/s 0.1-0.2
Average prolific yes, thousand pcs. 200
Survival rate of fingerlings from eggs, % 10
Average weight of fingerlings in November (when grown in carp ponds with a stocking density of 500 pcs/ha), g 50-70
Are zander raised artificially?
Many farmers are interested in the question: Are zander raised artificially? Growing zander in artificial conditions, for example in ponds, in cages, in a holding facility is quite possible. zander can lay eggs in a pond with an area of 200-300 m2, 3-4 m deep, with a clean sandy bottom. For spawning, zander digs a hole at the bottom with a diameter of up to 1 m, where it lays eggs. Therefore, to collect eggs in the pond, artificial nests for zander are installed, submerged to the bottom, which are willow rhizomes, pine needles tied into piles, or frames covered with nylon nets. Spawning in zander occurs at a temperature of 6-10°C and can occur at 5-20°C.
You can harvest zander breeders in the river or lake where it is found; to grow zander in the Krasnodar Territory, you can catch zander breeders in the Kuban estuaries in November-December. The peak migration of zander into the estuary is observed at 10-8°C water, the maximum movement of zander is at 2-4 a.m. The caught zander spawners are delivered to the winter quarters in live fish transport or other suitable container. On the Volga and in other places, slot boats with a length of 14, a width of 14.5, and a height of 0.9 m are used to deliver producers, where, according to the norm, 560-600 producers can be placed. Females and males of zander are harvested in a ratio of 1:1; female zander are 40 cm long, males - 30 cm.
Growing zander in artificial conditions - obtaining offspring
Producing zander offspring under controlled conditions. Is zander bred in captivity - to breed zander in captivity, it is necessary to build a spawning and rearing pond, a larval channel and purchase an incubation unit. A spawning pond for zander is a ground channel, on the bottom of which sand is laid in a layer of 10 cm. Its width is 1.2 m at the bottom and 2.4 m at the top; depth - 0.6 m; slopes -1:1. Water is continuously supplied to the walleye spawning pond, where a constant water level is maintained.
It is necessary to make artificial nests for zander in advance in the form of terry mats from fine-mesh nylon fabric (hamsoros), stretched over wire frames measuring 0.5x0.2 m. The frames are fastened in pairs and laid on the bottom of the channel in a checkerboard pattern. The water flow in the channel is set to 0.1-0.2 m/s. The stocking density of the producers is 5 nests for zander per 2 linear meters. m spawning tank. The ratio of producers is 5 females to 5-7 males. Spawning takes place at a temperature of 8-12°C. The working fertility of zander is 200 thousand eggs.
After caviar is found in an artificial nest for zander, the nest is placed in an incubation installation, consisting of a bathtub 1.6 m wide, 2.1 m long and 0.4 m high. A wave movement of water is created in the apparatus, for which a self-tipping bucket. When filled with water, the bucket tips over and creates a wave over the spawning nest. The bath is designed to incubate about 7 million zander eggs. Water consumption for 1 bath is 0.5 l/s. Larval survival rate is 50%.
Size of the larval tray: width - 1 m, length - 2-3 m, depth - 0.6 m. The larvae are kept in the trays for 2-3 days after hatching, then transferred to nursery ponds. The survival rate of zander larvae is 70%.
Growing zander in artificial conditions - raising fry
In nursery ponds, the density of fry is 300-500 thousand pcs/ha when grown for 20-25 days, when they reach an average weight of 0.5 g. The survival rate of zander fry is 25%. With longer cultivation, the planting density is reduced to 50-100 thousand pcs/ha; survival rate - 75%. As a rule, zander with an average weight of 0.5 g is an active predator, eating large invertebrates - mysids, gammarids or fry of other fish. Therefore, it is planted for growing in polyculture with other fish at a density of 300-500 fish/ha. In this case, the weight of fingerlings is 50-70 g; the survival rate of zander fry is 65%.
Growing zander in artificial conditions - wintering zander
Zander winters in hibernations 2-3 m deep, with a mud-free bottom and water exchange for 3-5 days. Yearlings overwinter at a planting density of up to 120 thousand pcs/ha. The planting density of older fish is 50 thousand pieces/ha. In winter, young of the year feed on large invertebrates: mysids, water donkeys, beetle or dragonfly larvae, and small fish. zander is an active cannibal.
Growing zander in artificial conditions - obtaining marketable zander
In the 2nd year, zander are raised in feeding ponds where there are a lot of trash fish. With sufficient nutrition, the average weight of zander is 200-500 g. In the absence of weed fish (the main food for zander), it is recommended to plant carp in the feeding pond at the rate of: 1-2 nests/ha, the fry of which will provide the zander with food for the whole year, at a density of zander 500-600 pcs/ha. In addition to carp, any other spawning fish, such as crucian carp or tench, is also suitable. Additional fish productivity due to zander -1-1.5 c/ha.
Some features of growing zander in a pond Among the features of growing zander in ponds, the following can be noted.
To grow zander in a pond, you need a pond with dense soil at the bottom and a well-planned bed. The depth of the pond should be at least 1.5 m. zander does not tolerate shallow reservoirs with a depth of 1 meter.
Raising the water temperature to 30 C has a depressing effect on fish.
For growing zander in a pond, a pond in which aquatic vegetation occupies less than 30% of the area is suitable. The more overgrown the pond is, the less weight the zander gains; this is a clear pattern. Small fish hide in thickets of macrophytes, while zander prefer to hunt in water clear of vegetation. Therefore, even the presence of a large number of trash fish in an overgrown pond will not ensure the possible growth of zander. So an overgrown pond can reduce the weight of zander by a third.
If the pond is overgrown with tough vegetation, this interferes with fishing; when water is drained from the pond, marketable fish may linger in overgrown areas, where they die.
When growing zander in a polyculture with carp, the number of carp yearlings must be no lower than standard, otherwise the zander will eat the carp.