THựC NGHIệM NUÔI TÔM CàNG XANH (MACROBRACHIUM ROSENBERGII DE MAN, 1897) VớI MậT Độ KHáC NHAU TRONG AO ĐấT

Abstract

The experiment on giant freshwater prawn (Macrobrachium rosenbergii) culture was carried-out in Long An village, Long Ho District and Long Phu village, Tam Binh District,VinhLongProvincefrom May to November, 2003.  Two different stocking densities of 8 (treatment 1) and 12 juvenile/m2 (treatment 2) were randomly designed in six ponds of 1000 - 1200 m2 /each.  The initial size of  prawns were 0.46 - 0.71 g, 3.12 - 3.43 cm.  Prawns were fed by 50 % pellet feed (32 ? 36 % of protein) and 50 % freshwater trash fish.  Feeding rate and feeding frequency were 3 ? 7 % /total body weight /day and two times per day, respectively.  The results showed that the water quality in cultured system such as water temperature, water pH, transparency, oxygen, N-NH4+, N-NO2- and H2S were acceptable values for the freshwater prawn growing and developing.  The survival rate of freshwater prawn in earthen ponds obtained in treatment 1 (39.8 ±  2.2 %) was not significantly higher (P > 0.05) than those in treatment 2 (34.9 ± 2.2 %) after 180 days.  The growth rate of prawn obtained in treatment 1 (0.22 g /day) was significantly higher (P < 0.05) than that in treatment 2 (0.18 g/day).  The highest yield of freshwater prawn trial in earthen ponds was 1,130 kg/ha.  Freshwater prawn culture at 8 juvenile/m2 in earthen ponds could be utilized for improving farmer?s income in theMekongDelta.

Tóm tắt

The experiment on giant freshwater prawn (Macrobrachium rosenbergii) culture was carried-out in Long An village, Long Ho District and Long Phu village, Tam Binh District,VinhLongProvincefrom May to November, 2003.  Two different stocking densities of 8 (treatment 1) and 12 juvenile/m2 (treatment 2) were randomly designed in six ponds of 1000 - 1200 m2 /each.  The initial size of  prawns were 0.46 - 0.71 g, 3.12 - 3.43 cm.  Prawns were fed by 50 % pellet feed (32 ? 36 % of protein) and 50 % freshwater trash fish.  Feeding rate and feeding frequency were 3 ? 7 % /total body weight /day and two times per day, respectively.  The results showed that the water quality in cultured system such as water temperature, water pH, transparency, oxygen, N-NH4+, N-NO2- and H2S were acceptable values for the freshwater prawn growing and developing.  The survival rate of freshwater prawn in earthen ponds obtained in treatment 1 (39.8 ±  2.2 %) was not significantly higher (P > 0.05) than those in treatment 2 (34.9 ± 2.2 %) after 180 days.  The growth rate of prawn obtained in treatment 1 (0.22 g /day) was significantly higher (P < 0.05) than that in treatment 2 (0.18 g/day).  The highest yield of freshwater prawn trial in earthen ponds was 1,130 kg/ha.  Freshwater prawn culture at 8 juvenile/m2 in earthen ponds could be utilized for improving farmer?s income in theMekongDelta.

Key words: Freshwater prawn, Stocking density, Feeding rate

Title: Experimental culture of giant freshwater prawn (Macrobrachium Rosenbergii De Man, 1897 ) at different stocking densities in earthen ponds