by
A.R. EL BOLOCK and W. LABIB
Institute of Oceanography and Fisheries
Alexandria, U.A.R.
CARP CULTURE IN THE U.A.R.
Abstract
The two varieties of common carp (scale carp and mirror carp) have been successfully introduced in the U.A.R. Most of the experiments and culture of carp were conducted in Barrage, Serow and Manzallah Farms. The first two farms are experimental while the last one is a commercial farm.
Carp spawned with satisfactory results in cement tanks with hard bottom. Egg collectors made of palm leaves covered with red palm fibres are used for attachment of eggs. Nursing experiments showed that 75,000 to 100,000 carp fingerlings, about 10 cm in length can be obtained per hectare of nursing ponds in about one month.
Examination of the Egyptian carp stock revealed the fact that only 17.13 percent of the examined fish possessed desirable body characters. After careful selection of the mothers, this ratio increased to 67.95 percent. Such improvement was reflected in the production per hectare, which was much higher in the case of the selected fish.
From carp production experiments conducted in Serow ponds, it was found that rearing carp fry alone produced 377 kg/ha (gain in weight) under natural conditions. By the addition of adult tilapia, a total production of 711 kg/ha was secured. Rearing a combination of carp fry, mullet fry and adult tilapia produced 800 kg/ha. Carp fry and indigenous fishes produced an average of 1,088 kg/ha. All these combinations were produced under natural conditions.
One-year-old carp, mullet and adult tilapia with feeding and fertilization produced 1,218 kg/ha. Rearing of tilapia as a supplementary fish with carp in our ponds is highly recommended.
200 kg per hectare can be produced from rearing carp in rice fields in two to three months. Rearing carp in only half of the rice fields in Egypt will produce about 30,000 metric tons every year.
No disease of any importance has affected our carp or caused great mortalities.
LA CARPICULTURE DANS LA R.A.U.
Résumé
Les deux variétés de carpe commune (la carpe “à écailles” et la carpe “miroir”) ont été introduites avec succès dans la R.A.U. La plupart des expériences d'élevage ont été menées dans les établissements piscicoles de Barrage, Serow et Manzallah. Les deux premières sont des stations expérimentales et la dernière est un établissement commercial.
Les carpes se sont reproduites de manière satisfaisante dans des bassins cimentés à fond dur. Des collecteurs d'oeufs en feuille de palmier recouverts de fibres de palmier rouge sont utilisés pour permettre la fixation des oeufs. Des expériences ont montré qu'en étang d'alevinage on pouvait obtenir, en un mois environ, de 75 000 à 100 000 carpillons de 10 cm per hectare.
Des prélevements sur le stock égyptien de carpes a révélé que 17,13 pour cent seulement des poissons examinés possédaient les caractéristiques physiques souhaitables. Une sélection attentive des mères a permis de porter ce taux à 67,95 pour cent. Cette amélioration s'est répercutée sur la production à l'hectare qui était beaucoup plus élevée dans le cas des poissons sélectionnés.
Des expériences de production menées dans les étangs de Serow ont montré que l'élevage de carpillons seuls produisait 377 kg/ha (gain en poids) dans des conditions naturelles. En ajoutant des tilapia adultes, on a obtenu une production totale de 711 kg/ha. Avec une combinaison d'alevins de carpe et de mulet et de tilapia adultes la production est passée à 800 kg/ha. Avec des alevins de carpes et des espèces indigènes on a obtenu en moyenne 1088 kg/ha. Toutes ces associations ont été essayées dans des conditions naturelles.
Avec un apport de nourriture artificielle et d'engrais, on a obtenu, en associant carpes d'un an, mulets et tilapia adultes, une production de 1218 kg/ha. L'élevage du tilapia comme espèce accessoire avec la carpe est fortement recommandé dans nos étangs.
L'élevage de carpes dans les rizières permet de produire 200 kg à l'hectare en deux ou trois mois. L'adoption de cette pratique dans la moitié seulement des rizières égyptiennes permettrait de produire 30 000 tonnes chaque année.
On n'a jamais constaté en Egypte de maladies importantes de la carpe ayant provoqué de fortes mortalités.
EL CULTIVO DE CARPAS EN LA R.A.U.
Extracto
En la R.A.U. se han introducido con éxito las dos variedades de carpa común: carpa escamosa y carpa de espejos. Casi todos los experimentos, así como el cultivo de carpas, se realizaron en las granjas de Barrage, Serow y Manzallah. Las dos primeras son experimentales en tanto que la última es una granja comercial.
La carpa desovó con satisfactorios resultados en depósitos de cemento con fondo duro. Para que se adhieran los huevos se emplean colectores hechos de hoja de palma cubiertos de fibras de palma roja. Los experimentos de cría mostraron que en un mes, aproximadamente, se pueden obtener de 75.000 a 100.000 jaramugos de carpa de unos 10 cm de longitud por hectárea de estanque de cría.
Un exámen de las poblaciones de carpas egipcias reveló el hecho de que sólo el 17,13 por ciento de los peces examinados poseían los caracteres físicos deseables. Después de una cuidadosa selección de las madres esta proporción aumentó al 67,95 por ciento. Tal mejora se reflejó en la producción por hectárea que fué mucho más elevada en el caso de los peces seleccionados.
En los experimentos de producción de carpas realizados en los estanques de Serow se comprobó que criando únicamente jaramugos de carpa se lograron 377 kg/ha, (aumento de peso) en condiciones naturales. Mediante la adición de tilapias adultas, se obtuvo una producción total de 711 kg/ha. Criando simultáneamente jaramugos de carpa, jaramugos de lisa y tilapias adultas se obtuvo una producción de 800 kg/ha. Los jaramugos de carpa y los peces indígenas dieron un promedio de 1.088 kg/ha. Todas estas combinaciones se criaron en condiciones naturales.
Carpas de un año, lisas y tilapias adultas, con alimentación artificial y fertilización, produjeron 1.218 kg/ha. Es muy recomendable la cría en estanques del país de tilapia como pez suplementario de la carpa.
En dos o tres meses se pueden obtener 200 kg/ha con la cría de la carpa en arrozales. La cría de la carpa en la mitad solamente de los arrozales de Egipto produciría unas 30.000 toneladas métricas anuales.
Ninguna enfermedad de importancia ha afectado a nuestra carpa o ha causado mortandades grandes.
The total fish production in the U.A.R. from the sea and inland waters was recently estimated to be about 124,159 metric tons. About 50 percent of this quantity is derived from natural inland waters, i.e. from the river Nile and two lakes.
The increasing demand for more fish has resulted in greater attention being paid to fish culture in Egypt. Various types of fish culture have been practised in the country, but it was not until 1934 that carp (Cyprinus carpio) culture was started. Since then carp culture has developed well all over the country.
Many papers have been written on carp in Egypt (Koura and El Bolock, 1960; Imam and Shaheen, 1960; Imam, Shaheen and Hashem, 1960 and FAO/UN, 1960 and 1963). In this paper it is proposed to review fully all information available on carp culture in Egypt, with special reference to the work done by the present authors on carp production under different conditions in the Serow Experimental Fish Farm.
Carp culture is practised in Egypt in many widely separated centres, the most important of which are Barrage, Serow and Manzallah farms.
This farm established in 1929 at El Kanatir El Khairia near Cairo, has 14 spawning, nursing and experimental ponds varying in area from 50 to 1,800 m2. The water supply is from an irrigation canal of the Nile. Every pond has an inlet and an outlet and is easily irrigated and drained. This farm is mainly meant for experiments in the acclimatization of exotic fishes. The common carp, Cyprinus carpio (scale type), the mirror carp, Cyprinus carpio v.specularis, the black bass, Micropterous salmoides, Tilapia mossambica, and the silver carp, Hypophthalmichthys molitrix, were received in this farm from 1934 to 1962. The suitability of indigenous fishes for culture is also studied here.
This farm was established in 1949 on the southern shore of lake Manzallah. It has 46 spawning, nursing, experimental and rearing ponds, and a total area of 12 ha. The water supply is taken from a nearly fresh-water canal near the farm. The spawning ponds (50 m2) are concrete built with hard bottom. The small experimental ponds are also concrete built with a muddy layer on the bottom. The nursing ponds (500 m2) and the rearing ponds (0.4 – 2 ha) are normal mud ponds and are easily filled and drained. This farm is considered as an ideal one for fish culture experiments. It is also used as a training centre for fish culture in Egypt.
This farm located about 30 km south of the Serow Farm was established in 1957. It consists of 38 spawning and nursing ponds varying in area from 50 to 1,000 m2, and 15 rearing ponds 6 ha each. In addition, there is a large water area of about 280 ha. The water of this farm is slightly brackish (chlorinity from 1.1 to 8.6 g/l). However, a connection to the fresh-water canal is proposed and is now under construction. The ponds of this commercial farm are easily filled, but pumps are used for drainage.
The common carp (scale type) was introduced from Indonesia in 1934. Two hundred and two carp fingerlings varying in size from 5 to 8 cm were planted in Barrage ponds where they reached 46 cm in two years. Carp spawned successfully under good control in the spring of 1936 when the water temperature reached 22°C. Different methods for collecting carp eggs were used. The most successful of these methods was the use of the frame-like collectors made of palm leaves and covered with red palm fibres. The collectors carrying the fertilized eggs were transferred to well managed and clean nursing ponds where the eggs hatched and the fry were nursed for about one month. The large number of carp fingerlings thus produced were distributed to the private farms for rearing. However, this variety of carp was not appreciated by our people and later on in 1949, it was replaced by the mirror carp.
The mirror carp was introduced from France, in the Barrage Farm where their acclimatization and spawning was completely successful (Koura and El Bolock, 1960). In the Barrage Farm, mirror carp attained a relatively high rate of growth (about 18 cm in length and 123 g in weight) in its first year of life. However, still higher growth is attained in Serow Farm (see 4.2).
From Barrage Farm, the mirror carp was transferred all over the country. Mirror carp were even exported to Saudi Arabia and Syria. The results of carp introduction in Saudi Arabia are not known, but the carp sent to Syria and reared at Kalaat El Moudik Fish Farm have established successfully (Beckman, 1959; FAO/UN, 1962).
Mirror carp was first transferred to the Serow Farm in 1956. Spawning occurred successfully in cement tanks with no muddy bottom. When the bottom is muddy, the splashing of the spawners cause mud to deposit on the eggs, causing great losses. The usual palm leaf collectors (80 × 110 cm) are used for the attachment of eggs. About 22 to 25 of these collectors are placed obliquely along the sides of the spawning ponds. The collectors carrying the eggs are either transferred directly to the nursing ponds where the eggs hatch and the fry live up to the end of the nursing period, or are first transferred to hatching ponds and then the larvae are transferred to the nursing ponds in the required numbers. The last practice proved more beneficial since the survival ratio of the fry was better than in the first practice.
Experiments showed that an average of 75,000 to 100,000 carp fingerlings of about 10 cm length can be obtained per ha of well managed and fertilized nursing ponds. The nursing period is usually about one month. Carp fry produced in spring are more healthy and show better growth than those produced in autumn (September). This is due to the greater abundance of plankton in the ponds in spring.
The examination of 5,000 carp varying in age from 1 to 4 years revealed the fact that
only 17.13 percent possessed the desired body characters. These characters are: the
possession of a small head, absence of malformations of body and fin, presence of scales
only on the fin bases and a relatively high back. As regards the last character, the body
length/height ratio 
varies from 2.1 to 3. However, such ratio is elastic and can be
easily improved through external conditions (Schäperclaus, 1961). The remaining 82.87 percent
are considered bad in all characters. They possess big heads, malformations are common
on the body and fins, and scales are either lacking or badly distributed all over the body.
To improve the body characters of our carp stock, the best and easiest method i.e the selection
of the present mothers and the development of an excellent race of future mothers was
adopted in spring 1963. In 1965, 5,000 yearlings produced from well selected mothers were
examined. The new generation showed much improvement in body characters. The percent of
fish with the desired body characteristics reached 67.93 after selection.
The effect of the improvement in body characters on carp growth and consequently on production per ha is shown by the results given in Table I. In this experiment, two ponds 0.4 ha each were stocked with one-year-old carp at the rate of 1,000 ha. While the first pond was stocked with well selected carp, the second pond was stocked with unselected carp of the old stock. Supplementary food (cottonseed cake and rice bran, 1:2) at a rate of ten percent of the total fish weight was given in each pond. The loss was small in both cases. From the Table it is clear that the growth (gain in weight/individual fish) of the first group is 3.4 times more than that of the second group. Part of this increase in growth is attributed to the longer rearing period of the selected fish. However, the fish with good body characters are no doubt more healthy and more able to make use of the natural and additional food in the pond and thus grow faster than the others. This fast growth is reflected in turn in higher production per ha.
Table I
Effect of improvement in carp body characters on
growth and production
| Stocked fish | Stock No./ha | Av. wt of fish at stocking (g) | Duration of rearing (days) | Av. wt of fish at fishing (g) | Gain in wt/fish (g) | Per ha gain in weight (kg) |
| Selected carp | 1,000 | 85 | 378 | 800 | 715 | 708 |
| Unselected carp | 1,000 | 61 | 319 | 268 | 207 | 263 |
A series of experiments to determine carp production per ha is being carried out in the Serow Fish Farm. The purpose of these experiments is to find out the conditions that give the maximum production at the lowest cost. The experiments done in 1964–1966 are discussed below.
The ponds used for the experiments were 0.4 to 2 ha in water area. The water level ranges from 120 to 180 cm. The water supply is nearly fresh (chlorinity from 0.3 to 0.7 g/l). The ponds are rich in the natural food for fishes, both plankton and bottom fauna.
Fry as well as one-year-old selected carp were used in these experiments. Grey mullet (Mugil capito), both fry and one-year-old, as well as adult Tilapia were used as supplementary fish. Both mullet fry and adult Tilapia can be easily fished in large quantities from the nearby canals and drains. The species of Tilapia used were T. galilaea (60 percent), T. zillii (30 percent) and T. nilotica (10 percent). As supplementary food, cottonseed cake and rice bran at a ratio of 1:2 were given.
4.2.1 Carp cultured under natural conditions
Under the natural conditions, without fertilization or artificial feeding, the production amounted to 377.2 kg/ha (see Table II) in Serow Farm.
Table II
Carp fry production under natural conditions
| Stock (No. per ha) | Av. wt of fish at stocking (g) | Duration of rearing (days) | Loss percent | Av. wt of fish at fishing (g) | Gain in wt/fish (g) | Per ha gain in weight (kg) |
| 5,000 | 5 | 212 | 42 | 138 | 133 | 377.2 |
Total harvested fish = 402.2 kg + 45 kg of other fishes.
However, the bottom of the pond was well managed, i.e. it was left to dry for a long period and was lightly ploughed. About 45 kg of other fishes (mostly Tilapia and Lates niloticus) were also found in the pond.
The presence of Lates niloticus in the pond is no doubt responsible for the high loss of carp fry stocked. Riedel (FAO/UN, 1962) estimated the natural production of El Ghab ponds in Syria to be 350 kg/ha. In Israel 200 to 400 kg/ha can be produced under natural conditions (Jones, 1956). In Lebanon, 500 kg of carp per ha was found to be produced under natural conditions in Terbol Fish Farm at Bekka Valley (Timmermans, 1960). In some German ponds (at Wielenbach), an average of 94 and 102 kg of carp per ha was produced without feeding or fertilization. Further experiments on the natural productivity of our ponds are planned. However, we can safely say that 370 kg/ha can be produced under natural conditions in well managed ponds of Serow Farm.
4.2.2 Carp cultured with Tilapia under natural conditions
Rearing of carp fry together with Tilapia under natural conditions was also conducted in Serow ponds. The Tilapia spawned and propagated themselves in the ponds during the rearing period. The result of this association is shown in Table III. A production of 711.2 kg/ha of fish was obtained from the pond, 57.8 percent of which was carp, while the remaining 42.2 percent was Tilapia. The gain in weight of Tilapia could not be calculated due to the propagation of these species in the pond. The relatively low weight of individual carp may be due to crowding. However, the per ha carp production was not affected by the presence of Tilapia and an additional 300 kg was obtained due to Tilapia.
Table III
Carp fry and Tilapia produced under natural conditions
| Stocked fish No./ha | Av. wt of fish at stocking (g) | Rearing period (days) | Loss percent | Av.wt of fish at fishing (g) | Per ha gain in weight (kg) | Total harvested fish/ha (kg) |
| 5,000 carp | 5 | 196 | 7.6 | 89 | 386.2 | 411.2 |
| 1,250 tilapia | - | 361 | - | - | - | 300 |
Total = 711.2 kg/ha
4.2.3 Carp cultured with mullet and tilapia under natural conditions
A still higher fish harvest was obtained when mullet fry were added to the previous association (see Table IV).
Table IV
Carp fry, mullet fry and tilapia under natural conditions
| Stocked fish No./ha | Av.wt of fish at stocking (g) | Rearing period (days) | Loss percent | Av.wt of fish at fishing (g) | Per ha gain in weight (kg) | Total harvested fish/ha (kg) |
| 5,000 carp | 6 | 196 | 25 | 91 | 311.3 | 341.3 |
| 2,500 mullet | 2 | 277 | 48 | 83 | 99 | 104 |
| 1,250 tilapia | - | 313 | - | - | - | 355 |
Total = 800.3 kg + 65 kg of other fishes/ha
The new association produced 800 kg of the stocked fish per ha. An excess amount of 65 kg of other fish was also secured from the pond. The weight per individual carp produced is still lower than that in case of rearing carp fry alone. The per ha gain in weight of carp was also somewhat affected by the population density. However, the end result of this association under the conditions prevailing in the pond is not bad.
4.2.4 Carp cultured with indigenous fishes under natural conditions
Another important result was obtained when carp was reared together with indigenous fishes found in our natural waters. Nile water at the beginning of the flood season was introduced in a pond about two ha in area. In this pond carp fry were also stocked at a rate of 2,500 ha. At the end of the rearing period (190 days) a total harvest of 1,200 kg of fish was obtained. The production consisted of 55 percent Tilapia, 20 percent carp, 17 percent mullet (Mugil capito) and 8 percent other fishes including Labeo spp., Bagrus bayad, Clarias lazera and Lates niloticus. The last two species increased the loss of carp to about 70 percent. In a less fertile pond of the same water area, the same association produced 977 kg of fish per ha.
4.2.5 Intensive culture of one-year-old carp, mullet and tilapia
In order to find out to what extent rearing of one-year-old carp and mullet is beneficial, an association of one-year-old carp, mullet and tilapia was stocked at the stocking rates shown in Table V. In this case additional feeding (2,500 kg/ha) was given. The pond was also fertilized with organic fertilizer (cowdung) at the rate of 1,000 kg/ha. The fertilizer was applied in heaps along the margins of the pond.
From the Table it is evident that the loss was negligible in both carp and mullet. This is no doubt due to the fact that the stocked fishes were big enough to protect themselves. It is also found that the gain in weight per individual carp is 3.1 times and of mullet 3.6 times more than that attained in combined culture under natural conditions (see Table IV).
When we exclude the production of Tilapia in both associations (Tables IV and V), we find that rearing one-year-old carp and mullet produced 276.5 kg of fish flesh more than by rearing fry. If we consider the total harvested fish in both cases, we find that the one-year-old carp, mullet and adult tilapia association produced (with additional feeding and fertilization) 353 kg of fish per hectare more than the association shown in Table IV (excess fish found is included).
Table V
Rearing one-year-old carp, tilapia and mullet with
feeding and fertilization
| Stocked fish No./ha | Av. wt of fish at stocking (g) | Rearing period (days) | Loss percent | Av. wt of fish at fishing (g) | Per ha gain in weight (kg) | Total harvested fish/ha (kg) |
| 1,250 C | 55 | 371 | 0.8 | 320 | 328 | 396.8 |
| 1,250 M | 50 | 371 | - | 337 | 358.8 | 421.3 |
| 1,250 T | - | 371 | - | - | - | 400 |
Total = 1,218.1 kg/ha
C = Carp
M = Mullet
T = Tilapia
It was also noticed that the already ripe one-year-old carp had spawned in the pond. However, carp propagation was severely controlled by Tilapia. Tilapia are known to devour large quantities of carp eggs (Imam and Shaheen, 1960). So, there is no fear of overpopulation of the pond with carp fry when rearing one-year-old fish.
4.2.6 Conclusions and observations on carp production
From the results obtained in carp production in Serow ponds, it is concluded that 370 kg of fish flesh can be produced by growing carp fry under natural conditions. Rearing adult Tilapia together with carp fry has not only not decreased carp production, but has increased the total yield by 209 kg. The addition of mullet fry to the previous association has slightly affected carp production, but the total yield is still higher than that of carp alone by 398 kg, and of carp-tilapia combination by 89 kg.
Rearing a combination of one-year-old carp and mullet, and adult tilapia produced 1,218 kg of fish per ha, 418 kg more than the combination of carp fry, mullet fry and adult tilapia. The weight of the undesired fishes found in the ponds is not included in this comparison.
In the above combinations, tilapia production reached 32 to 55 percent of the total harvested fish. Since tilapia (i) is easily available for stocking, (ii) does not compete with carp for its natural food, and (iii) is much appreciated by consumers, its rearing as supplementary fish in our ponds is highly recommended.
Fish culture in rice fields is of great economic importance in many countries of the Far East such as Japan, China and Indonesia. In Egypt fish culture in rice fields was first started in 1954 (Saheen, Imam and Hashem, 1960). When carp from 20 to 56 g in weight are stocked in rice fields at a rate of 750 to 1,250 fish per ha and reared for about two to three months, a total catch of about 200 kg of carp can be obtained, the gain in weight being about 88 to 186 g per individual fish. At the same time, the rice crop itself can be increased by five to seven percent as a result of raising fish in rice fields.
In the U.A.R. we have about 300,000 ha of rice fields. If carp culture is practised in even half of this area, an amount of about 30,000 metric tons of fish can be obtained every year. Preparing carp fingerlings and yearlings for such vast areas of rice fields is a matter of great importance.
No disease that causes great mortality in carp has been recorded in our ponds. It is also fortunate that ascities (the infectious carp dropsy) has not infected our carp. The fish louse (Argulus pillucidus) has been recorded in the Barrage Farm in 1952, but it was easily controlled. In summer months with high water temperatures that reach a maximum of 33°C, some mortality occurs due to oxygen deficiency. However, this is easily controlled by letting fresh oxygenated water in the affected ponds.
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FAO/UN, 1960 Report to the Government of the United Arab Republic (Egyptian region) on the fishery investigations on the Nile River, the lakes and the pond farms in Egypt, 1958–59. Based on the work of Wilhelm F.J. Wunder. Rep.FAO/ETAP, (1243):32 p.
FAO/UN, 1962 Report to the Government of Syria on a fish culture project. Based on the work of Dietmar R. Riedel. Rep.FAO/EPTA, (1502):38 p.
FAO/UN, 1963 Second report to the Government of the United Arab Republic on fishery investigations on the Nile River, the lakes and the pond farms in Egypt, 1961 and 1962. Based on the work of Wilhelm F.J. Wunder. Rep.FAO/EPTA, (1640):16 p.
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