Ranta Esa
Integrative Ecology Unit, Department of Zoology, University of Helsinki, P. Rautatiekatu 13, SF-00100, Helsinki, Finland.
Oecologia. 1992 Jan;89(1):150-152. doi: 10.1007/BF00319028.
Recently Poulin (1991), using published data on Canadian freshwater fishes (60 species, three families), concluded that there is no difference in parasite species numbers between solitary and social species. Nor could he associate parasite diversity to host size, age or range of distribution. Analysing Poulin's data with somewhat differing methods I reached different conclusions. Recognising that reported parasite species number per host species is a function of research effort (also noted by Poulin), I use residuals of the regression model as a measure of standardized parasite species number. First, it turned out that solitary and social salmonids differ in parasite faunal richness. That is, solitary species harbour a smaller diversity than species that school outside the breeding season. Second, host distribution range clearly correlates with the richness of total parasite fauna of the species in the three families. This observation was recently confirmed for North American freshwater fish species by Chandler and Cabana (1991). Third, in Percidae host size and age are also correlated with parasite species diversity.
最近， Poulin（1991年）利用已发表的关于加拿大淡水鱼（60种，三个科）的数据得出结论，独居物种和群居物种之间的寄生虫种类数量没有差异。他也无法将寄生虫多样性与宿主大小、年龄或分布范围联系起来。用略有不同的方法分析Poulin的数据时，我得出了不同的结论。认识到每个宿主物种报告的寄生虫种类数量是研究工作量的一个函数（Poulin也指出了这一点），我使用回归模型的残差作为标准化寄生虫种类数量的一种度量。首先，结果表明独居和群居的鲑科鱼类在寄生虫区系丰富度上存在差异。也就是说，独居物种的多样性比在繁殖季节外成群的物种要小。其次，宿主分布范围与这三个科中物种的总寄生虫区系丰富度明显相关。Chandler和Cabana（1991年）最近对北美淡水鱼物种的研究证实了这一观察结果。第三，在鲈科中，宿主大小和年龄也与寄生虫物种多样性相关。
