Abstract:
Prolific breeding and production of high percentage of recruits are main problems in mixed-sex
Nile tilapia (Oreochromis niloticus) culture in earthen ponds. The current study assessed the efficiency of
different sizes of African sharptooth catfish (Clarias gariepinus) in controlling recruitment in mixed-sex Nile
tilapia cultured in tanks and its effect on growth performance, percentage survival and yield. Three treatments
consisting of triplicate ponds stocked with mixed-sex Nile tilapia in monoculture and in polyculture with large
(62.50 ± 3.26 g) and small (40.00 ± 2.68 g) African sharptooth catfish were fed on a 297.50 g kg-1 crude
protein diet for 126 days. Results showed that, the number of recruits was significantly lower in larger African
sharptooth catfish predator than smaller ones and monoculture of Nile tilapia. Polyculture with larger African
sharptooth catfish resulted in significantly higher growth performance of Nile tilapia. Large African sharptooth
catfish in polyculture reduced the amount of small, low-value recruits, while the yield of large and high value
Nile tilapia was increased. This study revealed that fish farmers can reduce prolific breeding, obtain higher
growth performance and produce larger size of marketable Nile tilapia by predominantly stocking ponds with
large African sharptooth catfish predator of at least 60 g.
