COMPARATIVE ANALYSIS OF THE GROWTH AND FOOD COMPOSITION OF ODONTOBUTIS OBSCURA IN RICE-FISH AND POND CULTURE MODES

In order to investigate the effect of different culture modes on the growth index and food composition of Odontobutis obscura, and to explore the relationship between O. obscura and bait organisms, we compared the rice-fish culture and pond culture of O. obscura, and the results showed that there was no significant effect of culture mode on the survival rate of O. obscura, which in rice-fish culture was slightly higher than that in pond culture. The body weight gain (BWG), relative weight gain rate (RWG) and wet weight specific growth rate (SGR_W) of O. obscura in rice-fish culture were all higher than that of pond-cultured O. obscura. The feeding rate and gastric congestion of rice-fish cultured O. obscura were lower than those of pond-cultured O. obscura, but their growth indicators were better. In addition, except for Macrobrachium nipponense, there were more species and occurrence of bait organisms in the digestive tract of rice-fish cultured O. obscura than pond-cultured O. obscura in all three samples. In summary, compared with pond culture of O. obscura, the growth performance of rice-fish culture of O. obscura is better, and the rice-fish culture system can provide more abundant food resources for O. obscura and effectively reduce the cost of breeding. The body length of O.obscura was related to the body weight in a power function with the equation W=3.0×10^–5 L^2.9183 (R²=0.879; n=146; P<0.05), which was allometric growth. The gape width of O. obscura was linearly related to its body length and the frontal sword length of M. nipponense, and the body length of M. nipponense was also linearly correlated with its frontal sword length and the body length of O. obscura.