Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.592488
Title: Farming of carp (Cyprinus carpio L.) in rice fields in the Nile delta
Author: Gindy, A. N. Z.
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 1988
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Abstract:
The Egyptian government is committed to the development of rice field fish culture systems as means of protein production. Trials on the growing of common carp (Cyprinus carpio L.) were conducted in Gharbia governorate in the middle of the Nile delta. The trials reported here have shown that fish could successfully be reared in the Egyptian rice fields. Different stocking rates were used varying from less than 1000 up to 5500 fry/ha. The relation between different stocking rates and final fish weight, length, mortality and production of fish was studied. With stocking rates over 20000 a significant reduct (P < 0.001) in fish weight, and length was observed and mortality also increased (P < 0.02). Supplementary feeding at stocking rates of over 2000 fry/ha resulted in a partial restoration of fish weight and length (P < 0.001). Feeding reduced mortality from 46.2 to 33.5%. The data indicates an increase in fish production with the increase in stocking rate up to 100/ha but there were insufficient trials to give a statistically significant results. The highest production achieved in the trials without feeding was 167 kg/ha with a mean value of 88 kg/ha. The highest production of all trials was 264 kg/ha in a fertile area with supplementary feeding and with additional dose of organic manure. A strong relation was found between carp growth and the quantity and quality of natural food in the rice fields. Carp grew rapidly following introducing with a specific growth rate of 24% /day but this fell to 4% per day by the middle of the season, towards the end growth fell to zero or even negative values corresponded with the depletion of the community of invertebrate food organisms. The abundance of phytoplankton in the rice fields could provide a rich environment for raising other species of fish such as silver carp (Hypophthalmichthys molitrix) and Sarotherodon niloticus. Significant numbers of accidentally introduced fish of other species, were found (Clarias lazera; catfish), Tilapia spp., Lates niloticus, Nile perch), the rice field could be a reliable source of tilapia fry in addition to consumption carp. With the development of cage culture system an integration between rice fish culture and cage culture could potentially be achieved with the small fish obtained at the end of the growing season could be restocked in cages. The average additional income obtained from the introduction of carp to the rice fields represent an increase of more than 20%. This profit was obtained with as little as 2.31% increase in the total costs of rice and fish. In addition less labour was needed for weeding, with one weeding instead of the normal three.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.592488  DOI: Not available
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