斜带石斑鱼工厂化育苗水体理化因子分析

Analysis of Physical and Chemical Factors of Sea Water in Commercial Breeding of Epinephelus coioides

以斜带石斑鱼育苗水体为研究对象,采用碎屑食物链为基础的工厂化育苗方法,研究了育苗期间水体中氨氮、硝酸氮、亚硝酸氮、pH、光照和溶氧等理化因子的变化以及相互之间的关系,探讨了进一步完善斜带石斑鱼育苗的方法。结果表明,随着育苗时间的增加,水体中硝酸氮和亚硝酸氮的质量浓度均表现出增加趋势,且呈现明显的线性变化关系:y=4.3854x0.287,R2=0.8625,水体的溶氧质量浓度均在5.7mg·L-1以上,pH变化范围为7.15～7.92。育苗后期氨氮质量浓度维持在5mg·L-1以上,温度变化范围为27～29℃,盐度变化范围为30～34,光照强度平均值变化范围为1075～2320lx,一天中水面直射光照射面积和时间也呈现一定的线性变化关系:y=0.0177x2-0.1878x+0.5243,R2=0.9799。育苗期间池底水的氨氮、硝酸氮、亚硝酸氮、溶氧和pH与表层、中层差异显著,鱼苗生长良好。

Sea water in the breeding ponds for commercial breeding of Epinephelus coioides based on detrital food chain was analyzed to observe the changes of and relation among its physical and chemical elements such as ammonia nitrogen,Nitrate （ NO3--N） ,nitrite （ NO2--N） ,dissolved oxygen,pH,etc. to improve its breeding method. With the breeding time going on,nitrate （ NO3--N） and nitrite nitrogen （NO2--N） content tended to increase and showed a significant linear relationship：y=4. 3854x0.287,R2 =0.8625; the dissolved oxygen content of the sea water was over 5. 7 mg·L-1 ; pH ranged from 7. 15 to 7. 92; the ammonia nitrogen content was above 5 mg·L-1 in the late stage of breeding; temperature ranged from 27 ℃ to 29 ℃ ; salinity changed from 30 to 34; average light intensity ranged from 1 075 lx to 2 329 lx; direct sunlight water area and hours during the day also showed a linear relationship,y = 0. 017 7x2-0. 187 8x ＋ 0. 524 3,R2=0.9799. The levels of ammonia nitrogen,nitrate （ NO3--N） ,nitrite nitrogen （NO2--N） ,dissolved oxygen and pH in the pond bottom were significantly different from those in the surface and intermediate layers of sea water. All the fries lived normally during breeding.