Resetarits W J
Department of Zoology, Duke University, 2770, Durham, NC, USA.
Mountain Lake Biological Station, Route 1, Box 105a, 27708 A 24136, Pembroke, USA.
Oecologia. 1995 Sep;104(1):31-38. doi: 10.1007/BF00365559.
The identification of potential competitors has been driven by the concept of limiting similarity. Lacking are explicit tests of interaction strength among morphologically similar and dissimilar species. I used the mottled sculpin, Cottus bairdi, as a focal species in an artificial stream experiment designed to compare the effect of intraspecific competition to interspecific cometition from two very different species: a congener, the Kanawha sculpin (C. carolinae ssp.), and an unrelated species, the fantail darter (Etheostoma flabellare). The differences in morphology between these two species generate specific predictions under limiting similarity regarding the likelihood of competition and its relative strength: the congener should be a more important potential competitor. Increased fish density had a strong effect on the multivariate response of survival and growth, and on the relative condition of C. bairdi, indicating competition. The effect of additional C. bairdi or Kanawha sculpins were roughly equal, but the effect of E. flabellare was significantly greater. The most important potential impact on C. bairdi came from interspecific competition by a species that is smaller and very different in morphology, contrary to predictions based on limiting similarity.
对潜在竞争者的识别是由极限相似性概念驱动的。目前缺乏对形态相似和不相似物种间相互作用强度的明确测试。在一项人工溪流实验中，我将斑驳杜父鱼（Cottus bairdi）作为重点研究物种，该实验旨在比较种内竞争与来自两个截然不同物种的种间竞争的影响：一个同属物种，卡诺瓦杜父鱼（C. carolinae ssp.），以及一个非相关物种，扇尾镖鲈（Etheostoma flabellare）。根据极限相似性，这两个物种在形态上的差异对竞争可能性及其相对强度产生了特定预测：同属物种应该是更重要的潜在竞争者。鱼类密度的增加对生存和生长的多变量反应以及对斑驳杜父鱼的相对状况有强烈影响，表明存在竞争。额外的斑驳杜父鱼或卡诺瓦杜父鱼的影响大致相同，但扇尾镖鲈的影响显著更大。对斑驳杜父鱼最重要的潜在影响来自一个体型较小且形态差异很大的物种的种间竞争，这与基于极限相似性的预测相反。
