Channel catfish (Ictalurus punctatus) monoculture ponds stocked with 10,000/ha of mixed- size catfish were compared to ponds stocked additionally with blue tilapia (Tilapia aurea). Ponds stocked with 5000/ha young-of-the-year blue tilapia produced 236 kg/ha less catfish, but tilapia biomass increased by 1020 kg/ha, averaging 233 g/fish. Ponds stocked with sexually mature tilapia in Aprilto provide forage to the catfish had increased catfish production but a poorer food conversion radio. Ponds stocked with sexually mature tilapia in June or July had catfish production and FCR's similar to the controls. Dissolved oxygen was significantly lower than the controls in all polyculture treatments. Zooplankton biomass and secchi disc visibility were significantly lower than the controls in three of four polyculture treatments. Chlorophyll a was slightly, but not significantly, less than the controls. The major benefit of tilapia/catfish polyculture was the reduction of channel catfish off-flavor. Catfish in polyculture treatments were off flavor 8.3% of the times sampled, compared to 62.5% for catfish reared in monoculture. The addition of tilapia to catfish ponds is a practical, effective means of reducing the incidence of off-flavor in channel catfish.
Torrans, Les and Lowell, Fran
"Effects of Blue Tilapia/Channel Catfish Polyculture on Production, Food Conversion, Water Quality and Channel Catfish Off-flavor,"
Journal of the Arkansas Academy of Science: Vol. 41
, Article 22.
Available at: http://scholarworks.uark.edu/jaas/vol41/iss1/22