Edwards D D, Bush A O
Department of Zoology, Brandon University, Manitoba, Canada.
J Parasitol. 1989 Apr;75(2):225-38.
This paper reports patterns of similarity and overlap in species presence and patterns of linear distribution of intestinal helminths in 22 avocets from 4 populations. Avocets collected from ephemeral bodies of water in Alberta and Manitoba had communities composed largely of species that are avocet specialists plus some that are host generalists. The composition of helminth communities in these hosts was similar to that reported in earlier surveys of avocet helminths. There was little evidence for competition between helminth species in these communities. In contrast, avocets collected from permanent bodies of water in Alberta had communities composed largely of species that are specialists in various duck species, particularly lesser scaup. These helminths were superimposed on the normal community, fitting into linear gaps along the intestine but also overlapping the distributions of avocet specialists. These lesser scaup specialists exhibit interactive patterns amongst themselves and, to some extent, with avocet specialists. Helminth communities in avocets from ephemeral bodies of water have vacant niches and are largely isolationist in nature. Those in avocets from permanent bodies of water are saturated and are more interactive in nature.
本文报告了来自4个种群的22只长脚鹬体内肠道蠕虫的物种存在相似性和重叠模式以及线性分布模式。从艾伯塔省和曼尼托巴省的临时水体中收集的长脚鹬，其体内的蠕虫群落主要由长脚鹬特有的物种以及一些宿主广适性物种组成。这些宿主中蠕虫群落的组成与早期对长脚鹬蠕虫的调查结果相似。在这些群落中，几乎没有证据表明蠕虫物种之间存在竞争。相比之下，从艾伯塔省的永久性水体中收集的长脚鹬，其体内的蠕虫群落主要由各种鸭类物种（特别是小潜鸭）的特化物种组成。这些蠕虫叠加在正常群落之上，沿着肠道分布于线性间隙中，但也与长脚鹬特化物种的分布重叠。这些小潜鸭特化物种之间以及在一定程度上与长脚鹬特化物种之间呈现出相互作用的模式。来自临时水体的长脚鹬体内的蠕虫群落存在生态位空缺，本质上大多是隔离主义的。而来自永久性水体的长脚鹬体内的蠕虫群落是饱和的，本质上更具相互作用性。
