对虾养殖池水域环境细菌的动态变化

THE BACTERILAL VARIATION IN THE WATER ENVIRONMENT OF CULTURED PRAWN POND

于1990年6月下旬-10月初期间，每隔7－10d在大连市金州区董家沟镇养虾场突池定点采样一次，3h内带回实验室进行细菌培养计数，研究对虾养殖池水域环境中细菌的动态变化。结果表明，对虾养殖池水中异养菌和弧菌的数量变化与水温的变化趋势相同；6—7月末，细菌增长比较缓慢；8月初开始，细菌数量增长较快，8月中旬达到全年的最高值，异养菌为3．4×105cell／ml，弧菌为1．9×105cell／ml；而后随着水温的下降，水中细菌逐渐减少。底记泥浆中，细菌数量一直呈上升趋势，不受水温的影响；异养菌最高达6×107cell／ml，弧菌达1．5×106cell／ml。

Every 7-10 days from the last ten days of June to the be ginning of Octom-ber; 1990, a sample taken on fixed time fioma from a fixed cultured prawn pond at Dongjiagou town, Jinzhou district, Dalian city, was brought to the; aborary within three hours to study the bacterial development in dynamic state in the prawn pond environment. The result shows that in the prawn pond, the quality change of bacteria and vibrio and the temperature change of the water are the same:from June to the end of July the bacteria devepodment is slow; from the beginn-ing of August, the bacteria quantity grows fast; during the second ten days of August,the quality is the largest bacteria is 3.4 × 105 per ml. and vibrio 1.9×105 pet ml.Then with the decreasing of the water temperature bacteria in the water become fewer. However, the bacteria quality in the bottom mud is always rising, becaused the quality of bacteri is intluenced by increasing of metabolite and remaining bait,instead of the water temperature. The highest quality of bacteria reaches 6 × 107 per ml, and vibrio 1.5×106 per ml. The prawn's period of easily catching disea-ses tallies with the season when the bacteria quality is high in the water environ ment. The pH value of the water is in increasing tendency during the eaarly period,because of the propagation the of phytoplankton; during the midium and late period.the pH value is lowered by the organic acid which is decomposed from the organic.matter, eyacuation, remaining bait, and organis matter wnich containing nitrogen in the mud.