Gutiérrez Laura
Department of Biology, University of Houston, Houston, TX 77204-5513, USA Fax: (713)743-2636; e-mail:
Oecologia. 1998 Jun;115(1-2):268-277. doi: 10.1007/s004420050516.
Local patterns of adult distribution in organisms that disperse young as pelagic larvae can be determined at the time of recruitment through habitat selection or, shortly thereafter, through post-recruitment processes such as differential juvenile survivorship and interspecific competition. This study addresses the importance of habitat selection by recruits in establishing the local pattern of adult distribution in two sympatric Caribbean damselfish species, Stegastes dorsopunicans and S. planifrons. Both species inhabit shallow reefs but show little overlap in their distribution; S. dorsopunicans predominates in the reef crest and S. planifrons occurs primarily on the reef slope. Furthermore, S. dorsopunicans is associated with rocky substrate, while S. planifrons occupies live coral. The substrate cover follows a similar pattern with coral being much less common on the reef crest than on the reef slope. Monitoring recruitment every other day in reciprocal removal experiments and artificial reefs indicates that the observed pattern of local adult distribution is a product of habitat selection for both species. The presence or absence of conspecifics did not influence recruitment patterns for either species. Stegastes dorsopunicans recruited primarily to shallow, rocky areas, appearing to cue on both substratum type and depth. Stegastes planifrons recruited exclusively to coral substratum independent of depth. These results indicate that local adult patterns of distribution can be explained by habitat selection at recruitment, and that substrate type and depth may be important cues.
对于那些将幼体作为浮游幼虫进行扩散的生物,成年个体的局部分布模式可以在幼体补充时通过栖息地选择来确定,或者在补充后不久,通过诸如不同的幼体存活率和种间竞争等补充后过程来确定。本研究探讨了幼体在建立两种同域分布的加勒比雀鲷(背斑眶锯雀鲷和扁额眶锯雀鲷)成年个体局部分布模式中栖息地选择的重要性。这两个物种都栖息在浅礁区,但它们的分布几乎没有重叠;背斑眶锯雀鲷在礁顶占主导地位,而扁额眶锯雀鲷主要出现在礁坡上。此外,背斑眶锯雀鲷与岩石基质相关联,而扁额眶锯雀鲷占据活珊瑚。基质覆盖情况呈现出类似的模式,珊瑚在礁顶比在礁坡上要少见得多。在相互移除实验和人工礁中每隔一天监测幼体补充情况,结果表明观察到的成年个体局部分布模式是这两个物种栖息地选择的产物。同种个体的存在与否对这两个物种的幼体补充模式均无影响。背斑眶锯雀鲷主要在浅的岩石区域补充,似乎是依据基质类型和深度来定位。扁额眶锯雀鲷仅在珊瑚基质上补充,与深度无关。这些结果表明,成年个体的局部分布模式可以通过幼体补充时的栖息地选择来解释,并且基质类型和深度可能是重要的定位线索。