Effects of stocking density and feeding duration in cage-cum-pond-integrated system on growth performance, water quality and economic benefits of Labeo victorianus (Boulenger 1901) culture Anne Mokoro 1 , Elijah Oyoo-Okoth 1,2 , Charles C. Ngugi 3 , James Njiru 1 , Joseph Rasowo 4 , Victoria Chepkirui-Boit 1 & David Manguya-Lusega 1 1 Department of Fisheries and Aquatic Sciences, Moi University, P.O. Box 1125, Eldoret, Kenya 2 Department of Aquatic Ecology and Ecotoxicology, Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Kruislaan 320, 1098, XH, The Netherlands 3 Ministry of Fisheries Development, P.O. Box 58187-00200 Nairobi, Kenya 4 School of Biological and Physical Sciences, Moi University, P.O. Box 3900 Eldoret, Kenya Correspondence: E Oyoo-Okoth, Department of Fisheries and Aquatic Sciences, Moi University, P.O. Box 1125 Eldoret, Kenya. E- mail: elijaoyoo2009@yahoo.com Abstract We evaluated the effect of varying cage stocking density (60, 90 and 120 fish m À3 ) and feeding duration (10, 30 and 60 min) in a cage-cum- pond-integrated system on growth performance, water quality and economic benefits in Labeo victo- rianus culture. Interactions between stocking den- sity and feeding duration significantly (P < 0.05) affected the fish growth performance and yields in the cages-cum-pond system. Stocking density of 60 fish m À3 resulted in the highest growth in cages and in ponds regardless of the feeding dura- tion, but produced lower yields than at stocking density 90 fish m À3 . The lowest Apparent Food Conversion Ratio (AFCR) in cages occurred at stocking density of 60 fish m À3 and feeding dura- tion of 30 min. Growth performance in the open ponds declined with increased feeding duration of the caged fish. Survival in cages and in the open ponds decreased with increased cage density, but was not affected by feeding duration. Low dis- solved oxygen were recorded, at stocking density of 120 fish m À3 , the lowest DO occurred when feeding of caged fish lasted 60 min. Growth perfor- mance, water quality and economic benefits in La- beo victorianus culture positively respond to interaction between stocking density and feeding durations. Keywords: Cages-cum-pond system, feeding dura- tion, growth performance, Labeo victorianus, stocking density Introduction Rearing fish in either cages or semi-intensive ponds alone may produce low yields to sustain profitability in commercial aquaculture, beside the obvious inef- ficient use of unit space. A management strategy based on the concept of integrating intensive and semi-intensive culture practices in cages and ponds simultaneously (cage-cum-pond-integrated system) has been suggested in an endeavour to increase unit fish production (Yi, Lin & Diana 1996; Yi & Lin 2001; Liti, Fulanda, Munguti, Straif, Waidbacher & Winkler 2005). In the system, part of the stocked fish is kept in cages, while the other part is nursed in the open water ponds. Fish in the cages are fed high protein artificial feeds (intensive part of the component), while fish in the open ponds are not fed. The uneaten artificial feed from the cage could be utilized by two different processes: direct con- sumption by pond fish and indirectly contributing to nutrients for natural feed after being decomposed. Therefore, the caged fish satisfy their bio-energetic needs from the cage wastes either directly as uneaten food or indirectly from natural pond productivity after decomposition (semi-intensive © 2013 Blackwell Publishing Ltd 1 Aquaculture Research, 2013, 1–13 doi: 10.1111/are.12112