Introduced Western Mosquitofish (Gambusia affinis) reduce the emergence of aquatic insects in a desert spring
Introduced Western Mosquitofish (Gambusia affinis) reduce the emergence of aquatic insects in a desert spring
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DOI：
10.1086/680381
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发表时间：
2015-02
影响因子：
1.8
通讯作者：
Steven S. Merkley;R. Rader;G. B. Schaalje
中科院分区：
文献类型：
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作者：
Steven S. Merkley;R. Rader;G. B. Schaalje
在供体食物网中引入的捕食者可以破坏猎物流向受体食物网中的消费者。我们在一个沙漠春天的中型生态系统，调查如何入侵的鱼类捕食者，西方食蚊鱼（食蚊鱼affinis），影响水生昆虫的通量陆地食物网。我们建立了单养和混养的西方食蚊鱼与2个本地物种：最小的鲢鱼（Iotichthys phlegethontis）和犹他州鲢鱼（Gila atraria）。我们测试的假设，引进西方蚊鱼会减少新兴的水生昆虫的生物量更强烈地比本地鱼类，河岸蜘蛛密度会下降，以应对新兴的水生昆虫减少。在该荒漠生态系统中，水生昆虫成虫占飞行昆虫群落的78 ± 2%，西方食蚊鱼对羽化的负面影响是当地鱼类的2倍。与无鱼对照相比，西方食蚊鱼使水生昆虫的总羽化生物量减少了62 ± 8%，美洲丽蝇减少了90 ± 4%，摇蚊减少了34 ± 4%。本地鱼类都没有减少摇蚊的出现，但都减少了C。美洲鲢鱼（犹他州鲢鱼：85 ± 3%，最小鲢鱼：78 ± 3%）和犹他州鲢鱼与无鱼对照相比显著减少总羽化41 ± 5%。此外，一种模式的延迟出现的蠓在鱼治疗相比，无鱼控制建议一个潜在的重要的非致命性影响的能量流从沙漠泉水陆地消费者的鱼。
Introduced predators in donor food webs can disrupt the flow of prey to consumers in recipient food webs. We used mesocosms in a desert spring to investigate how an invasive fish predator, Western Mosquitofish (Gambusia affinis), affected the flux of aquatic insects to terrestrial food webs. We established monocultures and polycultures of Western Mosquitofish with 2 native species: Least Chub (Iotichthys phlegethontis) and Utah Chub (Gila atraria). We tested the hypotheses that introduced Western Mosquitofish would reduce the biomass of emerging aquatic insects more strongly than native fish, and that riparian spider density would decline in response to decreased emerging aquatic insects. Adult aquatic insects constituted 78 ± 2% of the flying insect community in this desert ecosystem, and Western Mosquitofish had a 2× greater negative effect on emergence than native fish. Compared to the fishless control, Western Mosquitofish reduced the total emergence biomass of aquatic insects by 62 ± 8%, Callibaetis americanus by 90 ± 4%, and chironomids by 34 ± 4%. Neither native fish reduced the emergence of chironomids, but both reduced the emergence of C. americanus (Utah Chub: 85 ± 3%, Least Chub: 78 ± 3%), and Utah Chub significantly reduced total emergence by 41 ± 5% compared to the fishless control. Also, a pattern of delayed emergence of midges in fish treatments compared to the fishless control suggested a potentially important nonlethal effect of fish on the flow of energy from desert springs to terrestrial consumers.