INTERSPECIFIC AND INTRASPECIFIC COMPETITION AMONG PINWORMS IN THE HINDGUT OF PERIPLANETA-AMERICANA
INTERSPECIFIC AND INTRASPECIFIC COMPETITION AMONG PINWORMS IN THE HINDGUT OF PERIPLANETA-AMERICANA
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DOI：
10.2307/3283276
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发表时间：
1993-02-01
影响因子：
1.3
通讯作者：
NOBLE, SJ
中科院分区：
文献类型：
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作者：
ADAMSON, ML;NOBLE, SJ
为了确定种间和种内因子在调节美洲大蠊后肠中蛲虫数量和繁殖力中的相对重要性，从2个种群中的每一个收集重复的蟑螂样品，每个包括一个成年雄性、一个成年雌性、一个晚龄和一个早龄，其中1个种群（混合）感染了Thalena sp.，Hammerschmidtiella diesingi和Leidynema approxylatum以及其他（分离株）仅感染最后命名的种。解剖蟑螂，估计后肠体积，并记录每种雌蠕虫的数量。解剖雌蠕虫，计数子宫卵数。肠道体积是除H外所有物种数量的显著预测因子。diesingi，其数量与2个种间伴生种的数量呈正相关。宿主内种间竞争的证据很少。在混合群体中，L. apapneumulatum发生与Thalapa sp.比预期的少，但这是唯一的负种间相互作用观察。生殖力与种间数量没有显着相关性，但与所有物种的种内数量呈强烈的负相关。Leidynema approxylatum发生在隔离和混合殖民地的强度大致相同。这些结果表明，每个物种的数量是独立调节的。通常情况下，这是通过不重叠的生态位发生的，但所有的证据都表明，在物种中存在广泛的生态位重叠。未发表的研究结果表明，L。apapellulatum和Thaplora sp.通过种内干扰限制自己的数量，这是其他几种蛲虫中报道的现象。生殖力降低可能是这种干扰的亚致死表现。我们建议，种内干扰持有的每个物种的数量低于承载能力，并允许它们的共存，尽管广泛的生态位重叠。在混合菌落中的患病率低于50%，在分离菌落中为100%。这表明，在混合殖民地的社会是一个2阶段的过程中，种间效应发挥了重要作用，在建立一个物种，但种内效应占主导地位的宿主环境的结果。
To determine the relative importance of inter- and intraspecific factors in regulating number and fecundity of pinworms in the hindgut of Periplaneta americana, repeated samples of roaches, each consisting of an adult male, an adult female, a late instar, and an early instar, were collected from each of 2 colonies, 1 colony (mixed) infected with Thelastoma sp., Hammerschmidtiella diesingi, and Leidynema appendiculatum and the other (isolate) infected with only the last-named species. Roaches were dissected, volume of hindgut estimated, and the number of female worms of each species was recorded. Female worms were dissected and the number of uterine eggs was counted. Gut volume was a significant predictor of numbers of all species except H. diesingi, numbers of which were correlated positively with those of its 2 interspecific associates. There was little evidence of interspecific competition within the host. In the mixed colony, L. appendiculatum occurred with Thelastoma sp. less often than expected, but this was the only negative interspecific interaction observed. Fecundity was not significantly correlated with numbers of interspecifics but was strongly and negatively correlated with numbers of intraspecifics in all species. Leidynema appendiculatum occurred at about the same intensity in isolate and mixed colonies. These results suggest that the number of each species is independently regulated. Typically this occurs through nonoverlapping niches, but all evidence points to there being broad niche overlap in the species. Unpublished findings suggest that L. appendiculatum and Thelastoma sp. limit their own numbers by intraspecific interference, a phenomenon reported in several other pinworms. Reduced fecundity is presumably a sublethal manifestation of this interference. We propose that intraspecific interference holds numbers of each species below carrying capacity and permits their coexistence despite broad niche overlap. Prevalence was below 50% in the mixed colony and was 100% in the isolate colony. This suggests that the community in the mixed colony is the result of a 2-stage process where interspecific effects play an important role in establishment of a species but where intraspecific effects dominate the in-host environment.