Zelmer D A, Arai H P
Department of Biological Sciences, University of Calgary, Alberta, Canada.
J Parasitol. 1998 Feb;84(1):24-8.
The independent effects of host age and size on parasite abundance are examined in yellow perch from Garner Lake in east-central Alberta. Older, larger perch tend to have more species of parasites combined with larger parasite infrapopulations. Sexual size dimorphism in perch generates 2 different size classes within each age class >2+ yr, thus allowing the opportunity to separate the effects of age and size on the recruitment of parasites by perch. The abundances of Diplostomum adamsi and Bothriocephalus sp. both increase with host age, whereas the increased abundances of Crepidostomum isostomum and Raphidascaris acus in larger fish are, in part, suggestive of size-specific feeding behaviors of the host. A combination of parasites with size- and age-dependent infrapopulations results in a size-dependent increase in infracommunity size. A comparison of variance-to-mean ratios within age classes to overall variance-to-mean ratios shows that the effects of host age and size on parasite recruitment do contribute to parasite aggregation.
在艾伯塔省中东部加纳湖的黄鲈中，研究了宿主年龄和体型对寄生虫丰度的独立影响。年龄较大、体型较大的鲈鱼往往有更多种类的寄生虫，且寄生虫种群数量也更大。鲈鱼的两性体型差异在每个大于2龄的年龄组中产生了两个不同的体型类别，从而有机会区分年龄和体型对鲈鱼寄生虫感染的影响。亚当氏复口吸虫和双槽头绦虫属的丰度均随宿主年龄增加而增加，而较大鱼类中同种等睾吸虫和尖锐蛔线虫丰度的增加，部分表明宿主具有特定大小的摄食行为。具有与大小和年龄相关的种群数量的寄生虫组合导致群落内大小随大小而增加。将各年龄组内的方差均值比与总体方差均值比进行比较表明，宿主年龄和体型对寄生虫感染的影响确实导致了寄生虫的聚集。
