热带海洋珍珠贝类立克次体(RLO)病研究——Ⅷ.养殖大珠母贝贝苗养成期群体RLO病流行病学研究  

Studies on rickettsia-like organism (RLO) disease of tropical marine pearl oyster——Ⅷ. Epidemiological investigation of RLO disease in juvenile populations of maricultured Pinctada maxima

作　　者：吴信忠[1] 潘金培[1] 江静波[2] 

机构地区：[1]浙江大学 [2]中山大学生命科学学院,广东广州510275

出　　处：《海洋学报》2003年第2期84-94,共11页

基　　金：中国科学院"八五"重点基金(KS85-121);国家重点基础研究发展规划(国家"973")资助项目(G1999012001)

摘　　要：大珠母贝人工养殖过程中,幼贝死亡是一个严重的问题。1993年11月至1995年5月,采用现场调查、实验室研究和数理分析相结合的方法,在海南省临高县新盈珍珠贝养殖场自然海区吊养的A,B,C3批养殖贝和陵水新村珍珠贝养殖场养殖池吊养的D批养殖贝的发病和死亡情况进行了流行病学凋查.结果显示,大珠母贝幼贝群体的死亡是以暴发性方式发生,幼贝群体的大批量死亡高峰一般发生在4～6月龄期,8个月以后随着龄期的延长,死亡率显著降低.幼贝群体死亡率与贝体平均体长的关系是4cm以下的贝体死亡率较高,1～3cm阶段处于死亡高峰期内,5cm以上的贝体死亡率显著降低.大珠母贝幼贝群体的死亡率与类立克次体感染(即RLO平均感染严重度指数SI)之间存在显著的相关性,在RLO感染的高峰之后或当中部相应伴随贝群体死亡率的高峰,随着RLO感染的降低,贝群体的死亡率也明显降低。在4批养殖贝群体中,仅在A批养殖贝群体样本中发现有少量纤毛虫寄生(感染率为87.5％,感染强度为3.56个/10倍物镜).这几批幼贝群体的死亡与海水温度、盐度之间均无相关性。The death occurred in juvenile population was a severe problem in the course of Pinctada maxima artificial culture. With the methods of field investigation, histological study and statistic analyses, the epidemiological study were carried out on the disease and death in juvenile populations of Pinctada maxima in the Xinying Pearl Oyster Mariculture Farm of Lingao County(for the A, B and C batches of cultured juveniles hanged in the sea) and the Xincun Pearl Oyster Mariculture Farm of Lingshui County(for the D hatch of cultured juvenile hanged in the pond), Hainan Province from November 1993 to April 1995. The results show that the deaths occurred in juvenile populations of Pinctada maxima presented a outbreak pattern(Fig. 1). The peak of mortality rates, in general, occurred in 4-to 6-month old pearl oyster juveniles, and the mortality rates gradully declined with the extention of pearl oyster age after culturing 8 months(Figs. 4 - 6). The correlation between the mortality rates of juvenile populations and mean body lenths of juvenile populations (Figs. 4 - 6) show that the mortality rate become high under 4cm of mean body lenths of juvenile population and become obvious declined over 5cm of mean body lenths. The peak of mortality rate occurred in 1 -3cm of mean body lenths. The results of histological observation showed that rickettsia - like organism inclusions were common, histological widespread infective agent among every batches( A, B, C and D) of cultured juvenile populations. The mean severity indices(SI) of rickettsia - like organism(RLO) infection were positively correlated with mortality rates of juvenile populations. After or within every peaks of RLO infection were all accompanied with the peaks of mortality rales of host populations and the mortality rales declined with decreased RLO infection(Figs. 7 - 9). So the evidences of histological observation and epidemiology in this study indicated that rickettsia - like organism (RLO) may be as an important pathogenic organism of disease and dea

关 键 词：大珠母贝 类立克次体病 流行病学 养成期贝苗 

分 类 号：S944.3[农业科学—水产养殖]