不同技术措施控制杂色鲍暴发性流行病的效果比较

Effects of different rearing modes on controlling out-breaking epidemic disease in Haliotis diversicolor under intensive culture

杂色鲍 (Haliotisdiversicolor)鲍苗体长 18.12～ 2 3.82mm ,体重 0 .98～ 2 .5 6g ,在 5种模式下进行养殖 ,即 :1)养殖用海水以不同方式进行前处理 ;2 )以 2 4h不同补水倍数 ;3)不同“倒池”次数 ;4 )不同投喂次数投喂细基江蓠 (Gracilariatenuistipitata) ;5 )不同产地、相同规格的鲍苗比较养殖。模式 1)～ 4 )养殖周期均为 6个月 ,鲍苗取自广东陆丰 ;模式 5 )养殖周期为 1个月 ,鲍苗分别取自福建东山、广东汕尾及广东陆丰的养鲍场。结果显示 ,直接抽取海水的养殖池 2 4h内有机沉积物含量分别为单过滤海水池和双重过滤海水池的 4 .9和 5 .1倍 ,而不同处理海水养殖池中有机沉积物与鲍苗的成活率呈密切相关 ;2 4h内的补水量对水体理化因子及杂色鲍成活率影响极显著 ,未换水组的氨氮含量、弧菌数分别为“5倍补水组”的 1.3和 6 .9倍 ,而死亡率则为后者的 2 1.7倍 ;未“倒池”组单位面积的有机沉积物分别为倒池 1、2、3次的 1.2、3.5和 3.6倍 ,氨氮含量分别为 1.73、2 .3和 3.5倍 ,弧菌数量比实验组要大 2～ 4个数量级 ;投喂方式、次数及停喂对水质影响十分明显 ,“3d投喂 1次 +停喂 1次”组的成活率高于其他组 (x2 >x20 .0 5,P <0 .0 5 ) ,水体中的氨氮比其他各组减少 14 9%～ 4 6 2 % ,而弧菌量减少

The larval Haliolis diversicolor, body length 18.12- 23.82 mm and body weight 0.98- 2.56 g, were cultured under 5 different modes, which were Ⅰ using double filtrated seawater, single filtrated seawater and original seawater, respectively, as the culture water; Ⅱ the culture water was added 1, 3, 5 and 8 times, respectively, more than initial water volume within 24 h; Ⅲ the abalones were removed to the other ponds for 1, 2 and 3 times during 6 months culture; Ⅳ using Gracilaria tenuistipitata as diet to feed the larval abalones at intervals of 2, 5, 3, 7, 4 and 9 days, respectively; Ⅴ a comparison trial for the abalone larvae collected from three different areas. Modes Ⅰ Ⅴ took 6 months as culture period and the larvae were all from the farms in Lufeng (Guangdong Province), and mode V only took one month and the larvae were from Dongshan (Fujian Province), Shanwei (Guangdong Province) and Lufeng, respectively. The results show that: Ⅰ within 24 h, the organic sediment in direct seawater pond has the highest level which is 4.9 and 5.1 times as much as that in the ponds of single filtrated seawater and double filtrated seawater, respectively; Ⅱ the added water amount within 24 h has significant effects on the water physi chemical factors and larvae survival rate that in the control (no water added) the contents of ammonia N and Vibrio are 1.3 and 6.9 times as much as those in the '5 time water volume' pond, respectively, and correspondingly the survival rate is 21.7 times as much; Ⅲ in the no removal abalone group, the contents of ammonia N and organic sediments are higher than the other removal groups and so does the Vibrio number; Ⅳ the survival rate in the 'feeding at 5d intervals' group is the highest in the 6 feeding groups and ammonia N concentration and Vibrio numbers are the lowest; Ⅴ in the larvae from three different sampling sites, those from Lufeng (Guangdong Province) have the highest survival rate (98%) with 10 d mortality 0, and those from the other two farms have the survival rate of 0%-40% with 10 d mortality 88%-95%. The conclusion is that the out breaking diseases in H. diversicolor can be avoided by bettering aquaculture mode and technique.