检出虾肝肠胞虫(Enterocytozoon hepatopenaei)的凡纳滨对虾(Litopenaeus vannamei)群体的体长和体重关系

The Relationship of Body Length and Weight in the Litopenaeus vannamei Populations Detected Enterocytozoon hepatopenaei

中文关键词: 凡纳滨对虾  体长  体重  劳雷尔体重指数  虾肝肠胞虫

英文关键词: Litopenaeus vannamei  Biological length  Body weight  Rohrer’s ponderal index  Enterocytozoon hepatopenaei

中文摘要:

      对采自天津、浙江和山东等养殖场5个凡纳滨对虾(Litopenaeus vannamei)群体的442尾个体进行虾肝肠胞虫(Enterocytozoon hepatopenaei, EHP)的TaqMan探针荧光定量PCR检测，并测量各群体每尾对虾的生物学体长和体重。引入医学上的劳累尔(Rohrer)体重指数(Ponderal index, PI, W/L3)关系建立对虾体重(W)和体长(L)关系函数。结果显示，4个凡纳滨对虾的EHP阳性群体[平均体长为(5.37±1.19) cm]的体重指数PI平均值为(5.19±0.26)×10–3 g/cm3，EHP阴性群体的凡纳滨对虾群体[平均体长为(2.49±0.21) cm]为(7.96±0.51)×10–3 g/cm3，根据PI =a·L(b–3)的函数矫正EHP阴性和阳性群体的体长差异引起的PI差值后，同等体长EHP阳性群体的PI值为阴性群体的(70.5±8.7)%，表明同样大小的个体，EHP阳性群体的平均体重比阴性群体平均体重低30%；EHP阳性群体中凡纳滨对虾体长和体重的变异系数是EHP阴性群体的(2.39±0.93)和(2.05±0.86)倍，表现为对虾EHP阳性群体个体大小不均匀；EHP阳性群体体重偏差率是EHP阴性群体的2.34–3.45倍，体长相同时，EHP阳性的体重波动变大。

英文摘要:

      Microsporidia Enterocytozoon hepatopenaei (EHP) was detected using probe based real-time PCR from 442 shrimp coming from 5 farmed Litopenaeus vannamei populations in Tianjin, Zhejiang, and Shandong Province. The biological length and body weight of shrimp were measured individually. The Rohrer’s ponderal index (PI, W/L3) originally used in medical science was introduced in this study to establish the fuction of body weight (W) and biological length (L) of shrimp. The results showed that the PI of 4 EHP positive populations with an average biological length at (5.37±1.19) cm was calculated as (5.19±0.26)× 10–3 g/cm3, while that of the EHP negative population with an average biological length was (7.96±0.51)×10–3 g/cm3. After adjusting of the difference of PI caused by biological length according to the function PI=a×L(b–3), the PI of EHP positive populations was about (70.5±8.7)% of that of the EHP negative populations at the same biological length. It indicated that the average body weight of shrimp in an EHP positive population was about 30% smaller than that of shrimp with same size in biological length in an EHP negative population. The coefficient of variation (CV) of biological length and body weight in EHP positive populations was (2.39±0.93) times and (2.05±0.86) times of those in the EHP population, respectively, suggesting significant size variation in the EHP positive populations. The deviation ratio of actual body weight to body weight estimated on biological length in the EHP positive populations was 2.34 to 3.45 times of that in the EHP negative population, indicating the shrimp with same size in the EHP positive populations had greater fluctuation in body weight.