Studies On The Biological Purification Technology To Mainly Culturing Pond Of Ctenopharyngodon Idellus

Ctenopharyngodon idellus is one of precious and high economic valued aquatic animals. Ctenopharyngodon idellus has been intensively artificially fed in our country. However, the outbreak of diseases happened frequently in Ctenopharyngodon idellus culture, due to aquaculture water pollution caused by the baits and feces left in the pond. In order to improving the problem, the water from Ctenopharyngodon idellus culture pond was treated with Ecological Microorganisms, Ipomoea aquatica, alone or in combination. The effects of water purification were investigated.(1) Results showed that the treatment performance was the best in the different methods, when the water was purified by Ipomoea aquatic, and the performance can be enhanced when Ipomoea aquatic was combined with EM. The removal rates of ammonia nitrogen (AN), nitrite (NIT), total phosphorus (TP) in water were 78.95%,75%,77.78% respectively, after 90 days treating of Ipomoea aquatic. The removal rate of AN and TP treated by Ipomoea aquatica was much higher than those of EM. The removal rates of AN, NIT, TP treated by EM was much higher the blank group. The removal rates of ammonia nitrogen (AN), nitrite (NIT), total phosphorus (TP) in water were 37.23%,50%,54.29%, respectively, after 90 days treating of EM. Meanwhile, the two metheods can increase the content of dissolved oxygen and stabilize the pH value.(2) The effects of plankton composition were investigated. Results showed that the Ecological Microorganisms and Ipomoea aquatica could decrease the number and the biomass of Cyanophyta. Although Chlorophyta and Baeillariophyta dropped in general, the small type species increased. Moreover, generally plankton displayed the speed of decrease of biomass faster than numbers and the Shannon-Wiener index of diversity displayed the pond of Ipomoea aquatica was the biggest. Then small-size geneses of plankton appeared more common than great-size ones, which increased the feed for fishes. In conclusion Ecological Microorganisms and Ipomoea aquatica could adjust and improve the structure of plankton community in Ctenopharyngodon idellus culture pond.The effects of zooplankton composition were investigated. Results showed that the Ecological Microorganisms and Ipomoea aquatica could increase the number of Rotifera and Cladocera, In particular, the small-size geneses of Rotifera. The biomass of Copepoda and Protozoa dropped in general, the small type species increased. Moreover, the Shannon-Wiener index of diversity displayed the pond of Ipomoea aquatica was the biggest (H=1.36) after 30 days. Then Shannon-Wiener index of diversity by EM was 1.34 and the blank group was 1.29.(3) Mainly Culturing Pond of Ctenopharyngodon idellus treating by Ipomoea aquatica and Ecological Microorganisms after 90 days, showed that the Ctenopharyngodon idellus, Hypophthalmichthys molitrix and Aristichthys nobilis growed well and the mortality of them was very low. Comprehensive comparison of breeding benefit showed the pond of Ipomoea aquatica was the best,29227.12 yuan/hm~2. Moreover the Input and output ratio of Ipomoea aquatica and EM was 1:1.44. The breeding benefit of EM and blank was 27372.12 yuan/ hm~2,23563.48 yuan/hm~2.