INTERSPECIFIC COMPETITION CONTROLS ABUNDANCE AND HABITAT USE OF TERRITORIAL CARIBBEAN DAMSELFISHES
INTERSPECIFIC COMPETITION CONTROLS ABUNDANCE AND HABITAT USE OF TERRITORIAL CARIBBEAN DAMSELFISHES
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种间竞争控制加勒比地区雀鲷的数量和栖息地利用
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
D. R. Robertson
中科院分区：
文献类型：
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作者：
D. R. Robertson
种间竞争对热带礁鱼的丰度影响不大的普遍观点已经得到了一些实验的验证，所有这些实验都考察了种间竞争对招募和幼鱼数量的影响，而不是对成鱼丰度的影响。这项研究在巴拿马加勒比海地区进行，研究了一种常见的领地雀鲷，planifrons，是否限制了四种生态上相似的同系物在planifrons主要栖息地的丰富度：S. partitus和S. variabilis，通常出现在该栖息地，以及S. diencaeus和S. leucostictus，很少这样做。当planifrons在16个天然斑块珊瑚礁中几乎被消灭4-6年后，具有较小攻击性且大小为planifrons一半的S. partitus成年种群数量增加了一倍，并扩大了它们的活动范围，进入了以前几乎完全由planifrons成虫使用的微栖息地。钉螺的种群增加发生在移除钉螺后的1年内，持续发生，但仅达到最大值；最初去除后4年（约四代）。变异S. variabilis的侵袭性较弱，比planifrons小20%，在去除planifrons后，其成年种群数量也增加了一倍。S. partitus和S. variabilis的总种群在先前S. planifrons最密集的珊瑚礁上增加最多。然而，这两种植物的种群密度和生物量密度的增幅分别仅为清除前的- 70%和-40%。去除planifrons对S. diencaeus和S. leucosticus的丰度没有影响。从8个珊瑚礁中去除S. partitus 3年不影响S. planifrons或S. variabilis的丰度。在实验前后11年的成虫种群和小叶蝉的吸虫监测表明，去除拟南芥后，小叶蝉种群数量增加，总体丰度逐渐增加，但与异常高的吸虫期无关。因此，在密切相关的、生态相似的、领土珊瑚礁鱼类之间的不对称竞争有时会控制共享栖息地的丰度和微栖息地的利用。在不同营养类群的礁鱼中，种间的地盘性、体型和攻击性的差异导致了不对称的竞争能力。这类物种群内的种间相互作用常常影响它们对栖息地的利用模式。因此，种间竞争在限制珊瑚礁鱼类丰度方面所起的作用需要重新评估。
The prevailing notion that interspecific competition has little impact on the abundances of tropical reef fishes has been tested by few experiments, all of which examined its effects on recruitment and juvenile demography rather than on adult abundances. This study, in Caribbean Panama, examined whether a common territorial damselfish, Stegastes planifrons, limits the abundances of adults of four ecologically similar congeners in S. planifrons' primary habitat: S. partitus and S. variabilis, which commonly occur in that habitat, and S. diencaeus and S. leucostictus, which rarely do. When S. planifrons was nearly eliminated from 16 natural patch reefs for 4-6 yr, adult populations of S. partitus, which is less aggressive and half the size of S. planifrons, doubled and expanded their range into a microhabitat previously used almost exclusively by adults of S. planifrons. Population increases by S. partitus occurred within 1 yr of the removal of S. planifrons, were persistent, but only reached their maximum ;4 yr (and about four generations) after the initial removal. Adult populations of S. variabilis, which is less aggressive and 20% smaller than S. planifrons, also doubled following the removal of S. planifrons. Combined populations of S. partitus plus S. variabilis increased most on reefs where S. planifrons previously had been most dense. However, increases by those two species reached only --:~70% of the population density and -40% of the biomass density that S. planifrons had before the removals. Removal of S. planifrons had no effect on the abundances of S. diencaeus and S. leucostictus. Removal of S. partitus from eight reefs for 3 yr did not affect the abundances of S. planifrons or S. variabilis. Eleven years monitoring of adult populations and juvenile recruitment by S. partitus before and during the experiment show that its population increase after the removal of S. planifrons occurred while its overall abundance was gradually increasing, but was not associated with a period of unusually high juvenile recruitment. Thus asymmetric competition among closely related, ecologically similar, territorial coral reef fishes does sometimes control both abundances and microhabitat use in shared habitat. Interspecific territoriality and differences in body size and aggressiveness that lead to asymmetric competitive ability occur commonly among reef fishes in various trophic groups. Interspecific interactions within such groups of species often affect their patterns of habitat use. Hence the role that interspecific competition plays in limiting abundances of coral reef fishes requires reevaluation.