POLYCULTURE OF FRESHWATER PRAWNS, TILAPIA, CHANNEL CATFISH AND CHINESE CARPS

Abstract

ABSTRACTJuvenile freshwater prawns (Macrobrachium rosenbergii), fingerling channel catfish (Ictalurus punctatus), young‐of‐the‐year tilapia (Tilapia spp.), F‐1 hybrid Chinese carp (female Aristichthys nobilis x male Hypopthalmichthys molitrix), and grass carp (Ctenopharynqodon idella) were costocked into four replicate 0.05‐ha earthen ponds in 1983 and 1984 and cultured for 124–150 days, respectively. Stocking densities of prawns (20,000/ha), tilapia (2,500/ha), and grass carp (120/ha) were held constant during both years. However, in 1984 stocking densities of channel catfish and hybrid carp were reduced to 7,500/ha and 160/ha, respectively. Throughout each study, a commercial floating catfish feed containing 32% protein was broadcast into the ponds daily at 1600 hours. Feeding rates were adjusted daily to a maximum of 56 kg/ha/day in 1983 and 41 kg/ha/day in 1984.Average net production figures were strikingly similar during both years–3,180 kg/ha in 1983 and 3,150 kg/ha in 1984. Mean feed conversion values for all species combined were 1.4:1.0 and 1.0:1.0 in 1983 and 1984, respectively. Net production and mean individual weights of component species during 1983 were: prawns (445 kg/ha, x = 30 g), channel catfish (1,411 kg/ha, x = 180 g), tilapia (653 kg/ha, x = 284 g), hybrid carp (546 kg/ha, x = 1,186 g), and grass carp (127 kg/ha, x = 1,337 9). Net production and mean individual weights in 1984 were: prawns (287 kg/ha, x = 19 g), channel catfish (1,698 kg/ha, x = 263 g), tilapia (522 kg/ha, x = 291 g), hybrid carp (389 kg/ha, x = 4,430 g), and grass carp (253 kg/ha, x = 2,924 g). Mean survival of component species ranged from a low of 72.9% for tilapia in 1984 to 100% for grass carp in 1983 and 1984.