It is recommended that a demonstration full-pattern fish culture station be established on the western zone of the Isfahan area (near Yazd-abad) using a one and a half year production cycle. A good water supply is available for this purpose and the project could be staffed by three persons. It is advisable that the intensive method of fish cultivation be used.
It is recommended that the rice fields and village reservoirs of Mazandaran and Guilan provinces be utilized for rearing market-size fish. This could be a successful undertaking.
It is recommended that a demonstration fish hatchery be established near the village of Mollakala, Mazandaran province, to supply young fish to four existing village reservoirs.
Village reservoirs existing in the Caspian plains area should be given an overall survey for potential, and training of fish culturists should also be intensified, choosing as students inhabitants from villages with reservoirs to be used for the rearing of market-size fish.
In order to service the fish culture stations which will be created in the areas of Isfahan and the Caspian plains, it will be necessary to train skilled fish culturists at training courses, Fisheries Research Institute, Bandar Pahlavi.
AVERAGE MONTHLY TEMPERATURES OF THE AIR IN THE ISFAHAN AREA
Month | Average temperature of the air, °C | Number of days with below zero temperatures of the air | Below zero temperatures of the air, °C |
January | 4.6 | 17–26 | 4.0–11.4 |
February | 7.3 | 8–21 | 2.0–10.4 |
March | 10.8 | 4–5 | 1.0–4.0 |
April | 14.7 | - | - |
May | 21.6 | - | - |
June | 26.8 | - | - |
July | 28.5 | - | - |
August | 27.2 | - | - |
September | 23.0 | - | - |
October | 16.9 | - | - |
November | 10.6 | 5–8 | 2.2–5.2 |
December | 5.4 | 14–29 | 4.0–9.2 |
PROTEIN RATIOS AND FEEDING RATIOS OF FOODSTUFFS USED FOR SCALE CARP
Feed | Protein Ratio | Feeding Ratio | |||
Minimum | Maximum | Average | |||
1 | 2 | 3 | 4 | 5 | |
Cakes: | |||||
sunflower | 1:1 – 1:1.5 | 3 | 5 | 4 | |
flax | 1:2 | 4 | 6 | 5 | |
colza | 1:1.4 – 1:1.8 | 4 | 8 | 6 | |
rape | 1:1–5 – 1:1.7 | 4 | 6 | 5 | |
hemp | 1:2 – 1:3 | 5 | 8 | 6 | |
soy-beans | - | 4 | 6 | 5 | |
cotton | 1:2 – 1:3 | 4 | 6 | 5 | |
castor-oil plant | - | 8 | 10 | 9 | |
coriander | - | 8 | 10 | 9 | |
Wastes of grains and of flour production: | |||||
barley | 1:8 | 3 | 5 | 4 | |
maize | 1:9 | 5 | 7 | 6 | |
rice bran | - | 4 | 6 | 5 | |
wheat bran | 1:4 | 4 | 6 | 5 | |
grain grinding dust | 1:5 | 4 | 8 | 6 | |
coarse barley flour | 1:6 – 1:7 | 4 | 6 | 5 | |
seeds of weeds | 1:4 – 1:7 | 6 | 8 | 7 | |
Beans: | |||||
soy-beans | 1:2 | 3 | 5 | 4 | |
peas | 1:2.5 | 3 | 5 | 4 | |
vetch | 1:2 | 3 | 5 | 4 | |
lentil | 1:2.5 | 3 | 5 | 4 | |
lupin | 1:2 | 3 | 5 | 4 | |
Animal feeds: | |||||
pupae of mulberry | |||||
and oak silk worms | 1:0.8 – 1:1.1 | 2 | 3 | 2.5 | |
fish meal | 1:2 | 1.5 | 2.5 | 2 | |
blood meal | 1:0.08 | 1.5 | 2.5 | 2 | |
meat and bone meal | 1:0.1 | 1.5 | 2.5 | 2 | |
meat of dry molluscs | 1:0.2 | 2 | 5 | 3.5 |
CHARACTERISTICS OF PONDS OF ISFAHAN FISH CULTURE PROJECT
Serial No. | Categories of ponds | Number of ponds and their water surface area, hectares | |
1. | Stock ponds for scale carp and plant-eating fish spawners. The spawners are kept separately from young and market-size fish in ponds specially allocated for this purpose. Female spawners are kept in one pond and males in another one. Each pond's area is estimated on the basis of its natural fish productivity, the number of fish to be kept in the pond and the weight gained during one vegetation period. It is desirable that these ponds be situated near the spawning ponds. The stock ponds should be of running-water type and completely drainable. For this purpose water supply and outflow constructions should be built there. The maximum depth of each pond is 2.5 m and the minimum depth is 1 m. | one pond for females … | 0.015 |
one pond for males … | 0.015 | ||
2. | Recruit-stock pond. This pond is designed for mixed rearing of scale carp and plant-eating fish belonging to various age groups until they attain sexual maturity. At sexually mature age, this fish, if necessary, could be used for replacement of defective spawners. This pond's area is calculated as for the stock ponds. This pond should have water inlet and outlet constructions. The maximum depth of the pond is 2.5 m; the minimum depth is 0.5 m. | one pond … | 0.125 |
3. | Spawning ponds. These ponds are designed for breeding of scale carp. The brood fish spawn there. The larvae emerge from the eggs laid by females on the substrate. The larvae are kept in the spawning ponds till they change over to active feeding, when they are released into the rearing pond. Each spawning pond's water surface area is assessed on the basis of the planned number of brood fish which will spawn every year. It should not exceed 0.1–0.2 ha. One female and two males need 500 m2 area for spawning. The spawning ponds are constructed by the way of creation of earthen dikes around the chosen ground. Each pond is provided with a water inlet for water inflow from feeding canals into the pond and an outlet for draining water from the pond into drainage canals. The spawning ponds have an independent water supply and drainage system. Thick grass, which during spawning serves as a substrate for laying eggs, should be sown at the bottom of each pond. The bottom of the ponds should be carefully designed to ensure a complete drainage of the pond by means of small ditches dug through the centre of the pond's bed. The width of the ditch should not exceed 0.4 m and its depth should be 0.3–0.5 m. Average depth of the pond is 0.4–0.5 m. The maximum depth of the pond at the outlet does not exceed 1.5 m. The spawning takes place in 0.2–0.3 m deep shoals which should constitute no less than 40 percent of the pond's total area. During the spawning the water of the pond should not be running. | one main pond … | 0.050 |
one reserve pond … | 0.050 | ||
4. | Earthen live-boxes (small ponds). Designed for keeping of plant-eating spawners after the injection of the pituitary gland extract. The spawners are kept separately: female fish in a separate live-box and male fish in another. The dimensions of live-boxes recommended for this particular project are: length - 5 m; width - 2 m. The live-boxes should be provided with water inlets and outlets ensuring filling and speedy and complete drainage of water. The depth of the live-boxes is 0.8 up to 1.2 m. | one live-box for females … | 0.001 |
one live-box for males … | 0.001 | ||
5. | Rearing pond. This pond is necessary for rearing scale carp and herbivorous fingerlings and for keeping its young fish in winter season till the age of one year. The water surface area of the rearing pond is determined on the basis of its estimated natural fish productivity (kg/ha), the required number of fingerlings and envisaged average weight gain of a fingerling. The pond should be completely drainable. For this purpose drainage ditches should be dug through the bottom. The width of a ditch is 0.5 m and the depth is 0.5–0.6 m. The filling of the pond should take place from the canal via the inlet devices. It should be drained through the outlet. Both the water supply and drainage of the rearing pond should be independent. The maximum depth of the pond is 2 m, its minimum depth is 0.5 m. The rearing pond should be situated near the finishing pond. | one pond … | 0.168 |
6. | Finishing pond. The mixed rearing of scale carp and herbivorous market-size yearlings takes place in the pond. The area of the finishing pond is determined on the basis of the total area of the plot allocated for the fish culture project, capacity of water supply resources, total market-size fish production planned and envisaged yield from one hectare of pond area (kg). The finishing pond, like all the other ponds of the fish culture project, should have water outlets and inlets making possible a complete drainage of the pond. For this purpose, the design of the pond bed should provide a slope toward the outlet and a network of drainage ditches. Holes at the bottom should be filled up, hillocks should be levelled with the ground. When constructing the finishing pond, efforts should be made to reach the most efficient depths of 0.5 up to 2 m on the largest possible area. Depths exceeding 2 m should not take more than 10 percent of the total area of the pond. Shoals having depth up to 0.5 m should occupy approximately the same portion of the pond. The finishing pond's water supply should be independent from that of other ponds. | one pond … | 3.3 |
Eight ponds and two earthen live-boxes (small ponds) … | 3.725 |
PRODUCTION CYCLE AND CALENDAR PLAN OF ISFAHAN FISH CULTURE PROJECT
Serial No. | Description of operations | Approximate dates for performing the operations | Number of days |
1. | Filling of the spawning pond | 10/4 – 15/4 | 1 |
2. | Catching of scale carp spawners from the stock ponds and introducing them into the spawning pond | 11/4 – 16/4 | 1 |
3. | Spawning of scale carp | 11/4 – 20/4 | 1 |
4. | Filling of the rearing pond | 14/4 – 23/4 | 2 |
5. | Draining of the spawning pond | 21/4 – 30/4 | 1 |
6. | Introduction of scale carp fry into the rearing pond and releasing the spawners back into stock ponds | 21/4 – 30/4 | 1 |
7. | Filling of the earthen live-boxes | 29/4 – 30/4 | 1 |
8. | Catching of plant-eater's spawners from the stock ponds, injecting the pituitary gland extract and introducing the spawners into earthen live-boxes, where they will stay until ripening of the reproductive products | 1/5 – 3/5 | 3 |
9. | Draining of the earthen live-boxes | 3/5 – 5/5 | 1 |
10. | Extracting the reproductive products from the plant-eating fish, introducing them back into the stock ponds, insemination of extracted eggs and loading them into incubation apparatuses | 3/5 – 5/5 | 1 |
11. | Incubation of eggs and hatching of herbivorous larvae | 4/5 – 7/5 | 1–1½ |
12. | Keeping of the herbivorous larvae until the change-over to active feeding | 4/5 – 14/5 | 7 |
13. | Introduction of the herbivorous larvae into the rearing pond | 11/5 – 14/5 | 1 |
14. | Rearing of scale carp and herbivorous fingerlings in the rearing pond | 21/4 – 10/11 | 204 |
15. | Keeping of scale carp and herbivorous young fish in the rearing pond during the winter season | 10/11 – 1/4 | 140 |
16. | Filling of the finishing pond | 1/3 – 30/3 | 30 |
17. | Draining of the rearing pond | 30/3 – 31/3 | 1 |
18. | Transferring of scale carp and herbivorous young fish from the rearing pond to the finishing pond | 31/3 – 1/4 | 1 |
19. | Rearing of scale carp and herbivorous market-size yearlings+ in the finishing pond | 1/4 – 10/11 | 224 |
20. | Draining of the finishing pond | 11/11 – 16/11 | 6 |
21. | Catching and selling of the market-size fish | 11/11 – 16/11 | 6 |
ANNUAL REQUIREMENTS FOR WATER SUPPLY DURING FILLING OF PONDS IN ISFAHAN FISH CULTURE PROJECT (WITH REGARD TO SATURATION OF SOIL UNDER THE BOTTOM, FILTRATION AND EVAPORATION FACTORS)
Serial No. | Categories of ponds | Approximate dates for filling of ponds | Duration of filling of ponds, days (24 h) | Water consumption rate l/sec |
1. | Finishing pond | 1/3 – 30/3 | 30 | 24.0 |
2. | Spawning pond | 10/4 – 15/4 | 1 | 4.5 |
3. | Rearing pond | 14/4 – 23/4 | 2 | 14.5 |
4. | Earthen live-boxes (small ponds) | 29/4 – 30/4 | 1 | 0.4 |
DAILY REQUIREMENTS FOR WATER SUPPLY DURING PONDS' OPERATION IN ISFAHAN FISH CULTURE PROJECT (WITH REGARD TO FILTRATION AND EVAPORATION FACTORS)
Serial No. | Categories of ponds | Monthly water consumption rates, l/sec | ||||||||||||
I | II | III | IV | V | VI | VII | VIII | IX | X | XI | XII | |||
1. | Finishing pond | - | - | - | 1.9 | 3.8 | 5.7 | 5.7 | 5.7 | 3.8 | 1.9 | - | - | |
2. | Rearing pond | 0.1 | 0.1 | 0.1 | 0.15 | 0.2 | 0.3 | 0.3 | 0.3 | 0.2 | 0.15 | 0.1 | 0.1 | |
3. | Stock ponds: | for females | 0.1 | 0.1 | 0.1 | 0.15 | 0.15 | 0.2 | 0.2 | 0.2 | 0.15 | 0.15 | 0.1 | 0.1 |
for males | 0.1 | 0.1 | 0.1 | 0.15 | 0.15 | 0.2 | 0.2 | 0.2 | 0.15 | 0.15 | 0.1 | 0.1 | ||
4. | Pond for spawners' recruit stock | 0.3 | 0.3 | 0.3 | 0.4 | 0.4 | 0.5 | 0.5 | 0.5 | 0.4 | 0.4 | 0.3 | 0.3 | |
Total | 0.6 | 0.6 | 0.6 | 2.75 | 4.7 | 6.9 | 6.9 | 6.9 | 4.7 | 2.75 | 0.6 | 0.6 |
RECOMMENDED CAPACITY OF FISH HATCHERIES AND FISH CULTURE STATIONS SUPPLIED BY HATCHERIES (MAZANDARAN PROVINCE)
Name of hatchery | Species of young fish raised in the hatcheries | Number of young fish raised annually in the hatcheries, thousands | Fish culture stations annual yield of market-size fish, tons | ||
extensive method | intensive method | extensive method | intensive method | ||
“Lapoo” | Scale carp (Cyprinus carpio L.) | 42 | 210 | 30 | 150 |
Grass carp (Ctenopharyngodon idella Valenciennes) | 19 | 57 | 15 | 45 | |
Silver carp (Hypophthalmichthys molitrix Valenciennes) | 19 | 57 | 15 | 45 | |
Pike-perch (Lucioperca lucioperca L.) | 15 | 15 | 5 | 5 | |
Total | 95 | 339 | 65 | 245 | |
“Mollakala” | Scale carp (Cyprinus carpio L.) | 30 | 150 | 21.5 | 107.5 |
Silver carp (Hypophthalmichthys molitrix Valenciennes) | 14 | 42 | 11.0 | 33.0 | |
Pike-perch (Lucioperca lucioperca L.) | 10 | 10 | 3.5 | 3.5 | |
Total | 54 | 202 | 36.0 | 144.0 |
TROUT CATCHES IN THE LAR RIVER AND ITS TRIBUTARIES
Name of Game and Fish Department Guard Station | Number of Permits Issued | Number of Trouts Caught | Average Numberof Trouts Caught Per One Permit |
Pulur | 246 | 3 456 | 14.0 |
Delichai | 1 931 | 33 360 | 17.3 |
Gozaldareh | 412 | 6 754 | 16.4 |
Total | 2 589 | 43 570 | 16.8 |
DISTRIBUTION OF WATER CONSUMPTION IN THE PADJIM AREA
(million m3)
Kind of water consumption | 1 Variant | 2 Variant | 3 Variant |
Irrigation | 56.7 | 59.5 | 63.0 |
Municipal demands | 23.2 | 23.2 | 23.2 |
Production of electric power | 30.1 | 32.3 | 33.8 |
Total | 110 | 115 | 120 |
INDICES CALCULATED FOR THE FISH HATCHERY (ALL AGE GROUPS OF FISH)
Serial No. | Age Groups of Fish | Method of Fish Cultivation | ||||
Extensive | Intensive | |||||
Scale Carp | Silver Carp | Scale Carp | Silver Carp | Pike-perch | ||
1 | 2 | 3 | 4 | 5 | 6 | 7 |
1. | Number of annually raised yearlings (thous. of pcs.) | 30 | 14 | 150 | 42 | 10 |
2. | Average weight of a yearling (g) | 20 | 20 | 20 | 20 | 15 |
3. | Yearlings' total weight (kg) | 600 | 280 | 3 000 | 840 | 150 |
4. | Yearlings' survival rate during winter season (≈%) | 85 | 82 | 85 | 82 | 75 |
5. | Number of annually raised fingerlings (thous. of pcs.) | 35 | 17 | 175 | 51 | 13 |
6. | Average weight of a fingerling (g) | 20 | 20 | 20 | 20 | 14 |
7. | Fingerlings' total weight (kg) | 700 | 340 | 3 500 | 1 020 | 168 |
8. | Fingerlings' survival rate during vegetation period (≈%) | 70 | 50 | 70 | 50 | 60 |
9. | Number of 5–7 days old larvae or fry (thous. of pcs.) | 50 | 34 | 250 | 102 | 22 |
10. | Number of 5–7 days old larvae or fry which can be produced from one female's eggs(thous. of pcs.) | 150 | 250 | 150 | 250 | 130 |
11. | Number of spawners (pcs.): | |||||
females | 1 | 1 | 2 | 1 | 1 | |
males | 2 | 1 | 4 | 1 | 1 | |
12. | Reserve of spawners (pcs.): | |||||
females | 1 | 1 | 1 | 1 | 1 | |
males | 1 | 1 | 2 | 1 | 1 | |
13. | Total number of spawners (pcs.): | |||||
females | 2 | 2 | 3 | 2 | 2 | |
males | 3 | 2 | 6 | 2 | 2 | |
14. | Recruit-stock for future replacement of spawners (pcs.): | |||||
fingerlings | 24 | 30 | 36 | 30 | - | |
yearlings | 12 | 16 | 18 | 16 | - | |
2-year old fish | 6 | 8 | 9 | 8 | - | |
3-year old fish | 4 | 6 | 7 | 6 | - | |
4-year old fish | 3 | 3 | 6 | 3 | - | |
5-year old fish | - | 3 | - | 3 | - | |
6-year old fish | - | 2 | - | 2 | - |
PRODUCTION PROCESS AND CALENDAR PLAN OF THE FISH HATCHERY'S WORK
Serial No. | Description of Operations | Approximate dates for performing the operations | Number of days |
1 | 2 | 3 | 4 |
1. | Filling of the pike-perch rearing pond | 10/3 – 14/3 | 4 |
2. | Filling of the pike-perch spawning pond | 15/3 – 16/3 | 1 |
3. | Catching of pike-perch spawners at a fish catching station, transportation to the hatchery and releasing them into the spawning pond | 17/3 – 18/3 | 1 |
4. | Spawning of the pike-perch | 20/3 – 21/3 | 1 |
5. | Draining of the spawning pond and transfering the pike-perch larvae to the rearing pond | 29/3 – 30/3 | 1 |
6. | Rearing of pike-perch yearlings in the pond | 1/4 – 30/2 | 335 |
7. | Filling of the scale carp rearing pond | 12/4 – 19/4 | 8 |
8. | Filling of the scale carp spawning pond | 20/4 – 21/4 | 1 |
9. | Catching of the scale carp spawners from the stock ponds and transferring them into the spawning pond | 22/4 – 23/4 | 1 |
10. | Spawning of the scale carp | 23/4 – 24/4 | 1 |
11. | Draining of the spawning pond, transferring the scale carp fry into the rearing pond and releasing the spawners back to the stock ponds | 3/5 – 4/5 | 1 |
12. | Rearing of scale carp fingerlings in the pond | 5/5 – 1/12 | 205 |
13. | Filling of earthen live-boxes for keeping the silver carp spawners there | 26/4 – 27/4 | 1 |
14. | Catching of silver carp spawners from the stock ponds, injecting the pituitary gland extract and releasing the spawners into the earthen live-boxes to keep them there till ripening of the reproductive products | 27/4 – 28/4 | 1 |
15. | Repeated injection of the pituitary gland extract to the silver carp spawners | 28/4 – 29/4 | 1 |
16. | Draining of the earthen live-boxes and extracting the reproductive products from the silver carp spawners | 29/4 – 30/4 | 1 |
17. | Incubation of eggs and hatching of the silver carp larvae | 30/4 – 1/5 | 1 |
18. | Keeping of the silver carp larvae in meshy live-boxes till the change-over to active feeding | 1/5 – 8/5 | 7 |
19. | Release of the silver carp larvae from the meshy live-boxes into the rearing pond where the scale carp fry are already being kept | 8/5 – 9/5 | 1 |
20. | Rearing of the silver carp fingerlings in the pond | 10/5 – 1/12 | 200 |
21. | Keeping of young scale and silver carps in the rearing pond during the winter period | 1/12 – 5/4 | 125 |
22. | Draining of the rearing pond and putting the pike-perch yearlings on the market | 1/3 – 2/3 | 1 |
23. | Draining of the rearing pond and putting the scale and silver carps' yearlings on the market | 3/4 – 5/4 | 2 |
Note:
For carrying out the operations indicated in Table 11 and concerning the intensive cultivation of young fish, the fish hatchery will need three workers and one skilled fish culturist.
Establishment of a fish hatchery near the village of Mollakala, Mazandaran province, will be a powerful incentive to development of inland fisheries in the north of Iran where great potentialities do exist.
BIOTECHNICAL STANDARDS OF KUTUM AND COMMON CARP CULTIVATION
Serial No. | Description | Species | |
Common Carp | Kutum | ||
1 | 2 | 3 | 4 |
1. | Ratio of males and females to be observed during procurement of the spawners | 1:1 | 1:1.5 |
2. | Weight of a spawner (kg) | 1.5:1.8 | 1.0:1.5 |
3. | Actual fecundity of females (thous. of eggs) | 180 – 200 | 70 – 80 |
4. | Reserve of the spawners (%) | 10 | 5 |
5. | Water temperature at which the fish start spawning (°C) | 16 – 20 | 8 – 20 |
6. | Maximum number of males and females which can be planted in a spawning pond (pcs.) | 100 | - |
7. | Maximum number of spawners which can be released into a live-box for keeping them till ripening of reproductive products (pcs.) | - | 5 |
8. | Fertilization ability of artificially inseminated eggs (%) | - | 98 |
9. | Standard amount of eggs loaded into incubators of following types (thous. of eggs): | ||
Youschenko | - | 130 | |
Weiss | - | 55 | |
Sez-Grin | - | 55 | |
10. | Water consumption rate of an incubator (1/min) | - | 4 – 8 |
11. | Duration of eggs' incubation period (days) | 3 – 7 | 10 – 15 |
12. | Percentage of hatched embryos (%) | 20 | 75 |
13. | Period of keeping the larvae in the spawning pond and the special bath till the change- over to active feeding (days) | 5 – 7 | 3 – 5 |
14. | Yield of larvae which started active feeding after the stay in the spawning pond and the bath (%) | 60 | 90 |
15. | Natural fish productivity of the rearing pond (kg/ha) | 150 | 150 |
16. | Standard amount of actively feeding larvae which can be planted per one hectare of the rearing pond (thous. of pcs.) | 80 | 215 |
17. | Period of rearing the young fish (days) | 45 | 60 |
18. | Average individual weight of the reared young fish (g) | 2.5 | 1.0 |
19. | Yield of young fish from one hectare of the pond during the period of rearing (%) | 75 | 70 |
20. | Yield of young fish from one hectare of the pond during the rearing period (thous. of pcs.) | 60 | 150 |
CAPACITY OF THE SPAWNING-AND-REARING FISH CULTURE STATION ON THE NEKA RIVER, MAZANDARAN PROVINCE
Serial No. | Description | Species | |
Common Carp | Kutum | ||
1 | 2 | 3 | 4 |
1. | Amount of spawners procured annually taking into account the reserve (pcs.): | ||
females | 185 | 220 | |
males | 185 | 330 | |
total | 370 | 550 | |
2. | Number of spawning ponds (pcs.) | 4 | - |
3. | Area of a spawning pond (ha) | 0.25 | - |
4. | The spawning ponds' total area (ha) | 1.0 | - |
5. | Amount of spawners planted into each spawning pond (pcs.): | ||
females | 42 | - | |
males | 42 | - | |
total | 84 | - | |
6. | Amount of larvae, which started active feeding, in each spawning pond (thous. of pcs.) | 960 | - |
7. | Amount of eggs procured from females with the aim of artificial insemination (millions of pcs.) | - | 15 550 |
8. | Amount of fertilized eggs (millions of pcs.) | - | 15 240 |
9. | Amount of eggs loaded into one Weiss incubator (thous. of pcs.) | - | 55 |
10. | Number of Weiss incubators (pcs.) | - | 277 |
11. | Water consumption rate of all Weiss incubators (l/sec) | - | 18.5 |
12. | Total amount of larvae transferred from all Weiss incubators to the trays for keeping there till the change-over to active feeding (millions of pcs.) | - | 11 430 |
13. | Number of rearing ponds (pcs.) | 2 | 2 |
14. | A rearing pond's area (ha) | 24 | 24 |
15. | The rearing ponds' total area (ha) | 48 | 48 |
16. | Natural fish productivity of a rearing pond (kg/ha) | 150 | 150 |
17. | Amount of actively feeding larvae planted into each rearing pond (millions of pcs.) | 1 920 | 5 145 |
18. | Total amount of actively feeding larvae planted into the rearing ponds (millions of pcs.) | 3 840 | 10 290 |
19. | Yield of young fish from each rearing pond (millions of pcs.) | 1 440 | 3 600 |
20. | Total yield of young fish from the rearing ponds (millions of pcs.) | 2 880 | 7 200 |
21. | Average individual weight of the reared young fish (g) | 2.5 | 1.0 |
a. bottom-type | b. installed in the water |
Fig. 1. FEED TRAYS FOR FISH
Fig.2. DIAGRAM OF THE ISFAHAN FISH CULTURE PROJECT
Fig. 3. LAR RIVER & PROSPECTIVE ARTIFICIAL LAKE
Fig.4. DISTRIBUTION OF DEPTHS IN PROSPECTIVE ARTIFICIAL LAR LAKE
1 – 12 Drainage Canal 2 – 3 Rearing Ponds 4 Water Supply Canal 5 Pond for Recruit-Stock 6 – 7 Spawning Ponds 8 – 9 Stock Ponds 10 – 11 Earthen Live-Boxes 13 Eggs Incubation Room 14 Room for Feeds Storage 15 Laboratory 16 Room for Fertilizers Storage 17 Service Personnel Room 18 Room for Fish Culture Implements |
Fig. 5. DIAGRAM OF THE FISH HATCHERY MAZANDARAN PROVINCE
1 Neka River
2 Bulkhead gate
3 Water supply and drainage canal
4, 5, 6, 7 Spawning ponds
8 Room for eggs' incubation and keeping the larvae
9 Room for fish culture implements
10 Service personnel room
11, 12, 13, 14 Rearing ponds
Fig. 6. DIAGRAM OF THE SPAWNING AND REARING FISH CULTURE STATION ON THE NEKA RIVER, MAZANDARAN PROVINCE