混养奥尼罗非鱼对凡纳滨对虾固着类纤毛虫的影响

The effect of introducing Nile tilapia(Oreochromis niloticus)on the sedentarius ciliate in the white shrimp(Litopenaeus vannamei)cultured system

于2015年8—12月对混养奥尼罗非鱼的凡纳滨对虾池塘进行对虾体表固着类纤毛虫的研究。在显微镜10×10倍视野下纤毛虫个体数量处于1级(≥30个)情况下,试验池1~#、2~#和3~#池分别放养奥尼罗非鱼苗体长10.0 cm密度4 500尾/hm^2、体长2.1 cm密度15 000尾/hm^2、体长6.0 cm密度9 000尾/hm^2均可以使凡纳滨对虾体表的固着类纤毛虫个体数量降低到4级(≤3个),通过控制饲料的投喂量和投喂频率,每15天测定试验池对虾体表虫体个数,均处于4级(≤3个)水平,1~#、2~#和3~#池净利润分别为75 489、46 625、55 682元/hm^2。试验结果表明:混养一定数量的奥尼罗非鱼对凡纳滨对虾固着类纤毛虫疾病具有防治作用,为该类寄生虫导致的疾病防治提供参考。

Tile sedentarius ciliate on the surface of white shrimp Litopenaeus vannamei （Boone） in the Nile tilapia-shrimp polycuhure ponds was examined from August to December 2015. The biomass of sedentarius cili- ate was enumerated by a microscope under 10 x 10 magnification. Results showed that the biomass of sedentar- ius ciliate on the surface of L. vannamei decreased from Level 1 （ ≥ 30）to Level 4 （≤ 3） when the stocking biomass of Nile tilapia larvae was 4 500 ind/m^2 （1^#, 10.0 cm）, 15 000 ind/m2 （2^#,2.1 cm）,9 000 ind/m^2（ 3^#, 6.0 cm）. The biomass of sedentarius ciliate could be controlled at Level 4 with an interval of 15 days observation by regulating the amount and frequency of formulated feed. The net profits of finfish and shrimp in the 3 ponds were 75 489, 46 625, 55 682 yuan/hm^2. Results revealed that the polyculture of some Nile tilapia in the L. vannamei cultured system could reduce the biomass of the sedentarius ciliate and increase the economic bene- fits, and this polyculture could obtain an ecological and economic process to control the outbreak of sedentarius ciliate.