GROWTH PERFORMANCE OF FISH REARED UNDER DIFFERENT DENSITIES IN SEMI-INTENSIVE AND EXTENSIVE EARTHEN PONDS
Shaker, I., Abdel-Aal, M. (2006). GROWTH PERFORMANCE OF FISH REARED UNDER DIFFERENT DENSITIES IN SEMI-INTENSIVE AND EXTENSIVE EARTHEN PONDS. EKB Journal Management System, 10(4), 109-127. doi: 10.21608/ejabf.2006.1904
Ibrahim Shaker; Mohamed Abdel-Aal. "GROWTH PERFORMANCE OF FISH REARED UNDER DIFFERENT DENSITIES IN SEMI-INTENSIVE AND EXTENSIVE EARTHEN PONDS". EKB Journal Management System, 10, 4, 2006, 109-127. doi: 10.21608/ejabf.2006.1904
Shaker, I., Abdel-Aal, M. (2006). 'GROWTH PERFORMANCE OF FISH REARED UNDER DIFFERENT DENSITIES IN SEMI-INTENSIVE AND EXTENSIVE EARTHEN PONDS', EKB Journal Management System, 10(4), pp. 109-127. doi: 10.21608/ejabf.2006.1904
Shaker, I., Abdel-Aal, M. GROWTH PERFORMANCE OF FISH REARED UNDER DIFFERENT DENSITIES IN SEMI-INTENSIVE AND EXTENSIVE EARTHEN PONDS. EKB Journal Management System, 2006; 10(4): 109-127. doi: 10.21608/ejabf.2006.1904

GROWTH PERFORMANCE OF FISH REARED UNDER DIFFERENT DENSITIES IN SEMI-INTENSIVE AND EXTENSIVE EARTHEN PONDS

Egyptian Journal of Aquatic Biology and Fisheries
Article 7, Volume 10, Issue 4, September 2006, Page 109-127  XML PDF (192.57 K)
Document Type: Original Article
DOI: 10.21608/ejabf.2006.1904
View on SCiNiTO View on SCiNiTO
Authors
Ibrahim Shaker1; Mohamed Abdel-Aal2
1Limnology Department
2Aquaculture Department Central Laboratory for Aquaculture Research, Abbassa, Sharkia, Egypt.
Abstract
Effect of stocking density on fish performance has been investigated in earthen ponds over five months of growing period in a polyculture system including Nile tilapia, common carp, silver carp, mullet and African catfish. Experimental ponds have been allocated to various stocking rates of 1, 1.25, 1.5, 1.75, 10 and 14 fish/m3. The treatments of 10 and 14 fish/m3 represented the semi-intensive system, while lower densities represented the extensive calture system. Fish in all treatments received 25% crude protein pelleted fish feed at a rate of 3% of body weight that was adjusted throughout the growing period. Feed was offered twice/day for five days/week. Water quality has been monitored monthly. The physico - chemical analysis showed two distinct sets of values for the extensive and the semi-intensive stocking densities concurred with for the main water quality parameters, whereas the values of pH, E.C., salinity, alkalinity, hardness, total phosphorus and orthophosphate were significantly higher in extensive system than the semi-intensive one, while values of D.O, SD, NH3, NO2, NO3 were higher in the semi-intensive system compared to the extensive system. Plankton communities expressed as Chlorophyll "a" was significantly higher in the extensive ponds. Average production was significantly higher in semi-intensive ponds compared to the extensive ponds. However, for the main fish species (Nile tilapia), the average weight as well as the daily gain did not vary among treatments, while there were some differences with regard to average weight for other species. There was no difference concerning the condition factor in all treatments for any of the tested species. The economic analysis revealed increases in variable costs as well as higher net returns as the stocking density increased. However, the rate of return to capital percentage has decreased with the increase of the stocking density. The overall analysis suggested the semi-intensive system to be the most profitable system.
Keywords
polyculture; intensive; extensive; water quality; Plankton; Growth performance; tilapia; Mullet; carp; catfish
Statistics
Article View: 433
PDF Download: 650