EFFECTS OF PARASITIC CASTRATION ON GROWTH, REPRODUCTION AND POPULATION-DYNAMICS OF THE MARINE SNAIL CERITHIDEA-CALIFORNICA
EFFECTS OF PARASITIC CASTRATION ON GROWTH, REPRODUCTION AND POPULATION-DYNAMICS OF THE MARINE SNAIL CERITHIDEA-CALIFORNICA
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DOI：
10.3354/meps096229
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发表时间：
1993-06-01
影响因子：
2.5
通讯作者：
LAFFERTY, KD
中科院分区：
文献类型：
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作者：
LAFFERTY, KD
我研究了寄生去势器可以降低宿主种群密度的预测。对盐沼蜗牛 Cerithidea californica 的一项调查表明，蜗牛密度与阉割寄生蜗牛的幼虫吸虫的流行率之间存在负相关。进行了田间实验以确定吸虫幼虫影响蜗牛种群的机制。对蜗牛密度和吸虫流行率的控制表明，吸虫幼虫降低了蜗牛种群的繁殖能力，并导致寄生宿主的不同死亡率。此外，通过比较蜗牛生长率，检测了寄生蜗牛和未寄生蜗牛之间的竞争效应。正如预期的那样，这被认为是简单的密度效应，而不是由于寄生蜗牛的任何特殊品质所致。对沉积物中叶绿素 a 水平的分析表明，由于食物数量有限，可能发生了竞争。这些结果表明，幼虫吸虫可以通过减少钉螺繁殖、与寄生钉螺竞争食物以及增加寄生钉螺的死亡率来降低钉螺种群密度。
I investigated the prediction that parasitic castrators can reduce host population density. A survey of the salt marsh snail Cerithidea californica suggested a negative association between snail density and the prevalence of larval trematodes which castrate parasitized snails. Field experiments were conducted to determine the mechanisms by which larval trematodes might affect snail populations. Manipulations of snail density and trematode prevalence indicated that larval trematodes reduced the reproductive output of the snail population and caused differential mortality of parasitized hosts. Furthermore, an effect of competition between parasitized and unparasitized snails was detected by comparing snail growth rates. As expected this was deemed to be a simple density effect and was not due to any special qualities of the parasitized snails. Analysis of chlorophyll a levels in the sediment suggested that competition may have occurred due to limited amounts of food. These results suggest that larval trematodes can reduce snail population densities by reducing snail reproduction, competing with parasitized snails for food and increasing the mortality rates of parasitized snails.