美洲红点鲑和白斑红点鲑及其杂交子代幼鱼的生长曲线拟合

Growth modelling of Salvelinus fominalis and S.leucomaenis juveniles and their hybrid offspring

自2011年11月至2013年1月,对美洲红点鲑(Salvelinus fominalis)和白斑红点鲑(Salvelinus leucomaenis)及其杂交子代从受精卵到1年零两个月幼鱼的生长特性进行了研究。以美洲红点鲑和白斑红点鲑为亲本,建立2×2双列杂交组合,采用Logistic、Gompertz和Von Bertalanffy 3种动物生长模型对美洲红点鲑(A)和白斑红点鲑(B)及其杂交子代进行生长曲线拟合并分析比较其生长性能。实验设置自交组AA、BB和杂交组AB(A♀×B♂)、BA(B♀×A♂)4个实验组。根据模型拟合的R2值判断各组生长性能的拟合程度,并对其体质量、体长、成活率及肥满度进行比较。结果发现,Gompertz生长模型的拟合效果最好,R2均大于0.99,其中AB组生长优势明显。成活率由高到低依次为:AA、AB、BA、BB,但AA组与其他3组的成活率差异不显著(P>0.05)。增重率(g/d)和肥满度(g/cm3)等生长指标均由高到低依次为:AB、AA、BA、BB,各组间差异显著(P<0.05)。研究结果显示,正交子代(A♀×B♂)幼鱼生长性能明显高于反交子代(B♀×A♂)及其亲本,可见此杂交组合可能具有较高的推广潜力。

We studied the growth characteristics of juvenile Salvelinus fominalis and S. leucomaenis and their hybrid offspring from the fertilized egg stage to one year and two months of age （November 2011 to January 2013）. Next, we established diallel crosses. The specimens were collected from the water at Bohai station （Bohai Sea）. Growth function models（Specialized Logistic, Gompertz, and Von Bertalanffy） were used for fitting the length and weight growth pro-files of S. fominalis and S. leucomaenis juveniles and their hybrid offspring for analysis and comparison of their growth characteristics. The test comprised four groups, AA and BB （selfing groups）, AB（A♀×B♂） and BA（B♀×A♂） （hybridi-zation groups）. A denotes S. fominalis and B denotes S. leucomaenis. According to the degree of fit during model fitting of the commercial fish, we judged the value of each combination of R2 by comparing their body weights, body lengths, survival rates and relative fatness levels. The sum of residual squares for the models was compared with one another and the Gompertz growth function was the most accurate model for growth fitting with R2〉0.99, and an AB group ad-vantage was obvious. At the end of the experiment, the survival rates were AA〉AB〉BA〉BB, with no significant dif-ferences （P〉0.05） in the other three AA groups. Comparisons of growth rate （g/d）, condition factor （g/cm3）, and other growth indicators showed the following trend： AB〉AA〉BA〉BB, and the difference was significant （P〈0.05）, with relative growth in length and weight increasing with age. Differences in the growth indices showed the same trend. The direct hybrid （AB, A♀×B♂） growth performance was significantly higher than that of the reciprocal hybrid （BA, B♀×A♂） and its parents. Hence, the potential for high economic production in hybrids exists.