Polyculture of Nile tilapia ( Oreochromis niloticus) and Australian red claw crayfish ( Cherax quadricarinatus) in earthen ponds

Abstract

Nile tilapia ( Oreochromis niloticus) and Australian red claw crayfish ( Cherax quadricarinatus) were cultured alone and together in replicat 0.02 ha earthen ponds to assess the nature and intensity of species interaction in polyculture. Treatments were: (I) 10000 tilapia per hectare, (II) 10000 tilapia plus 25000 crayfish per hectare and (III) 25000 crayfish per hectare. All ponds were fed a 32% crude protein, pelleted catfish feed at monthly-adjusted rates based on stocked tilapia biomass. After 100 days of polyculture, ponds were harvested. Tilapia growth, reproduction and food conversion were adversely affected by the presence of crayfish ( P<0.01). Crayfish growth, incidence of intersexuality and percentage of berried females were not affected by the presence of tilapia ( P<0.01).