Open AccessWater Quality, Fish Production and Economics of Nile Tilapia, Oreochromis niloticus, and African Catfish, Clarias gariepinus, Monoculture and Polycultures
Author(s) -
Ibrahim Nabil,
Naggar Gamal El
Publication year - 2010
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/j.1749-7345.2010.00397.x
Subject(s) - clarias gariepinus , biology , oreochromis , nile tilapia , polyculture , catfish , fishery , aquaculture , tilapia , fish farming , monoculture , fish <actinopterygii> , ecology
Twelve 400 m 2 earthen ponds were used to test the effect of Nile tilapia, Oreochromis niloticus , African catfish, Clarius gariepinus, monoculture and polyculture on water quality, fish production and economic performance across a range of stocking ratios: 100% tilapia + 0% catfish, 75% tilapia + 25% catfish, 50% tilapia + 50% catfish, and 0% tilapia +100% catfish. All ponds were stocked at the rate of 3 fish/m 2 . Two‐way ANOVA showed that culture period explained more than 60% of variation in water quality variables while treatment was responsible only for about 11%. Net fish yields were 5.71, 9.84, 11.03, and 11.35 tones/ha corresponding with daily weight gains of 36.60, 63.08, 70.69, and 72.75 kg/ha/d in the 0% catfish, 25% catfish, 50% catfish, and 100% catfish treatments, respectively. Feed consumed was 7.59, 10.84, 13.48, and 17.03 tones/ha for the four treatments, respectively. Fish yield and feed consumption were highest in the catfish monoculture ( P < 0.05) followed by the 50% catfish, 25% catfish, and 0% catfish treatments.Net profit for both polyculture treatments was significantly higher than both monoculture treatments, although no significant differences were observed among polyculture or between the two monoculture treatments. The 25% catfish polyculture treatment generated the highest economic returns.