Resource partitioning or reproductive isolation: the ecological role of body size differences among closely related species in sympatry
Resource partitioning or reproductive isolation: the ecological role of body size differences among closely related species in sympatry
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DOI：
10.1111/j.1365-2656.2009.01645.x
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发表时间：
2010-03-01
影响因子：
4.8
通讯作者：
Sota, Teiji
中科院分区：
文献类型：
--
作者：
Okuzaki, Yutaka;Takami, Yasuoki;Sota, Teiji
P > 1。共存亲缘物种之间的体型差异是很常见的，但这些差异在缓解种间相互作用（如资源竞争和繁殖干扰）中的实际作用却知之甚少。地面甲虫属Carabus （Ohomopterus亚属）的本地组合通常由两个或两个以上不同大小的物种组成。通过对四种同翅目昆虫在同栖和共栖中的觅食和交配实验，研究了种间体型差异在分配食物资源或减少生殖干扰方面是否有效。由于同翅蝶幼虫只以蚯蚓为食，体型的差异可能与蚯蚓大小的分配有关。然而，幼虫对不同体型蚯蚓的选择和攻击成功率并没有表现出不同的体型，这表明以体型分配食物的可能性很小。相反，当体型差异较大时，种间交配行为（如配偶识别、交配和交配）受到阻碍；交配经常发生在体型差异较小的异居种之间。这些结果表明，物种之间的体型差异有效地减少了繁殖干扰，而不是资源竞争。虽然人们认为，在密切相关的共存物种中，体型差异在资源分配方面起作用，但它们可能主要是在生殖隔离方面起作用，从而促进物种共存。
P>1. Body size differences among coexisting related species are common, but the actual effect of these differences in mitigating interspecific interactions, such as resource competition and reproductive interference, is poorly understood.2. Local assemblages of the ground beetle genus Carabus (subgenus Ohomopterus) typically consist of two or more species of varying sizes. Through foraging and mating experiments using four Ohomopterus species in parapatry and sympatry, we examined whether interspecific body size differences are effective in partitioning food resources or reducing reproductive interference.3. Because larval Ohomopterus feed exclusively on earthworms, body size differences may be related to partitioning earthworms of different sizes. However, larvae did not exhibit differences in selectivity or attack success on earthworms of different sizes based on larval body size, indicating little possibility of partitioning food by body size.4. In contrast, interspecific mating behaviours, such as mate recognition, mounting, and copulation, were hindered when body size differences were large; copulation was frequently accomplished between parapatric species with smaller body size differences.5. These results suggest that body size differences between species effectively reduce reproductive interference, rather than resource competition. Although body size differences in coexisting closely related species have been considered to function in resource partitioning, they may function primarily in reproductive isolation and thereby facilitate coexistence of species.