author(s)
Md. Abdul Halim, MM Nabi and S Nahar

abstract
The present study was carried to optimize the stocking density of Vietnamese koi (Anabas testudineus) in marginal farmer earthen ponds in Kotalipara Upazilla under Gopalgonj district Bangladesh out from April to July 2015. Three stocking densities (treatments) were compared: ponds with 300, 350 and 400 individuals per decimal. All treatments (T₁, T₂ and T₃) were randomly imputed and in duplicate. SGR (%) value (2.01) was recorded in T₁ and the lowest (2.01) in T_3. The survival rates were 90±.20, 85±0.38 and 80±0.15 for T₁, T₂ and T₃ respectively. The FCR was 1.5±0.30, 1.75±0.35 and 1.85±0.14 in T₁, T₂ and T₃ respectively. The highest production was 6669.00 kg/ha in T₁, followed by T₂ (6246.63 kg/ha) and T₃ (6086.08kg/ha) respectively. The highest benefit or net return for T₁ Tk. 325941.40/ha and BCR of 1.54 followed by Tk. 146172.13/ha and BCR value of 1.22 in T₂ and Tk. 96171.92/ha and BCR value of 1.13 in T_3. The stocking density of 300 individuals per decimal was the most profitable system. More research will be needed to further optimize stocking density of Vietnamese koi in marginal farmer earthen ponds.