The Study On The Ecological Environmental Features Of Culture Monopterus Albus In Cages And Rice Fields And The Analysis Of Culture Benefit

This paper dealt with the ecological environmental characteristics of culture Monopterus albus in cages and rice fields. According the investigation of water quality and the species and biomass of phytoplankton and zooplankton, the main results are summarized as following:1.According to the data of water quality monitoring, the water diaphaneity ranged from 0.1 m to 0.35 m and the value of pH had a little change. The dissolved oxygen (DO) descended gradually, and the lowest value were only 1.9 mg/L, under the demanding value of normal activity. The level of total nitrogen(6.30mg/L) phosphorus(0.45mg/L)and COD(36.25mg/L) in the trial ponds increased steadily during the cultural time. With a comprehensive assess of water quality, the water was deeply in eutrophication. In the experimental rice fields, the value of pH had a little change; the DO ranged from 3.85mg/L to 4.80mg/L, but the situation was better than in ponds. The level of TN (1.88mg/L-3.65mg/L), TP (0.12mg/L-0.51mg/L) and COD (16mg/L-26mg/L) in the trial rice fields increased steadily during the cultural time, and lower than in ponds. The level of ammonium nitrogen ranged from 0.36mg/L to 0.56mg/L, and the nitrate nitrogen altered in the range from 0.4mg/L to 0.8mg/L in the rice fields.2.The phytoplankton identified from the trial ponds belongs 40 gena, 7 phyla. The phytoplankton biomass altered from 4.22 mg/L to 22.31 mg/L, averaging 12.29 mg/L. The diversity index of the phytoplankton (H =0.96) was relatively low. The zooplankton identified belongs to 19 species, and its biomass ranged from 3.75mg/L to 7.74mg/L, averaging 5.93mg/L. The diversity index of the zooplankton was relatively low too. In the cultured rice fields, the phytoplankton identified belonging 53 gena, 6 phyla. The average of biomass in the cultured rice fields was 19.28 mg/L, lower than the value in the no-cultured rice fields. In the culture rice fields, the zooplankton identified belonging 21 species, and its biomass ranged from 4.82mg/L to 8.68mg/L. The diversity index of the zooplankton was relatively low too. In the early phase, there war no a significant different about the diversity index between the cultured and no-cultured rice fields. In the latterphase, the diversity index in cultured rice fields was lower than the no-cultured. So it showed a nearly effect between the Monopterus albus and the plankton in the rice fields.3. On the base of economy analyse, the ratio of input to output were 1:1.21 in the cages, 1 .' 2.73 in rice fields. In conclusion, culturing Monopterus albus in rice fields was a tempting culture model.