感染刺激隐核虫的大黄鱼对低溶氧量的耐受力研究

Research on tolerance of Pseudosiaena crocea suffered from Cryptocaryon irritans disease to low dissolved oxygen

每年6月中下旬至7月初是福建省沿海养殖的大黄鱼刺激隐核虫病的发病高峰期,为明确患病大黄鱼暴发性死亡的原因,进行了患刺激隐核虫病大黄鱼对低溶氧量的耐受力试验。结果表明,病情越严重的鱼出现浮头、大量死亡时的溶氧量越高、耗氧率越低。健康鱼的窒息点和耗氧率分别为2.58 mg/L、332.4 mg/kg·h-1,而病情呈"+++"鱼的窒息点和耗氧率分别为3.83 mg/L、196.0 mg/kg·h-1。结合试验结果和养殖生产的实际情况,笔者认为患刺激隐核虫病的大黄鱼对低溶氧量的耐受力降低,易导致其暴发性大量死亡。

Late June and early July each year are the peak periods of Cryptocaryon irritans infection of Pseudosiaena crocea cultivated along the coastline of Fujian province. In order to investigate the causes of mas- sive death of sick Pseudosiaena crocea, we carried out an experiment on tolerance of Pseudosiaena crocea suf- fered from Cryptocaryon irritans disease to low dissolved oxygen. The result showed that the fish suffered from more serious disease, even floated head and died in large number, the dissolved oxygen in water was higher and the oxygen consumption rate was lower. The choke point and oxygen consumption rate for healthy fish were 2.58 mg/L and 332.4 mg/kg·h^-1 respectively, and those of fish infected diseases in the degree of ＂ ＋ ＋ ＋ ＂ were 3.83 mg/L and 196.0 mg/kg·h-1 respectively. Combining the experimental results with situation of Pseudosiaena crocea culture production, we concluded that the decreasing tolerance of Pseuclosiaena crocea suffered from Cryptocaryon irritans disease to low dissolved oxygen easily leaded to explosive death in a great deal.