Muñoz Alejandro A, Ojeda F Patricio
Departamento de Ecología, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Casilla 114-D, Santiago, Chile e-mail:
Oecologia. 1998 May;114(4):563-573. doi: 10.1007/s004420050481.
Although ontogenetic changes in resource use within species are common in animals, these changes have not been widely considered in studies of guild structure within communities. The occurrence of one or more shifts in resource use in an individual of a given species during its life should mean that it would also belong to different guilds at different life stages. We specifically addressed this issue by describing the feeding habits of ten species of carnivorous fishes occurring in tidepools in rocky intertidal areas along the coast of central Chile. Most of these species undergo clear ontogenetic dietary shifts and a feeding guild structure of this group of fishes was established that takes these dietary shifts into account. Each species was divided into a number of size classes. Dietary overlap values between both intraspecific and interspecific size-class pairs in the entire group of ten species were used to construct a phenogram of dietary similarity through an UPGMA cluster analysis. Numbers of guilds and their memberships were established objectively by applying a bootstrapping procedure. Four "ontogenetic" feeding guilds (OFGs), each consisting of size-classes of species, were recognized. The majority of species belonged to more that one guild. Interestingly, when the bootstrapping procedure was applied to a phenogram based on the diets of "taxonomic" or complete species, only one significant guild was found. The implications of these ontogenetic dietary shifts for interspecific interactions are substantial because the identity of the species with which each fish species shares resources change through their lives. The usefulness of taxonomic species for investigating potential competitive interactions in this assemblage is greatly undermined.
尽管物种内部资源利用的个体发育变化在动物中很常见，但在群落内 guild 结构的研究中，这些变化尚未得到广泛关注。给定物种的个体在其生命过程中出现一次或多次资源利用的转变，这意味着它在不同的生命阶段也应属于不同的 guild。我们通过描述智利中部海岸岩石潮间带潮池中出现的十种肉食性鱼类的摄食习性，专门解决了这个问题。这些物种中的大多数经历了明显的个体发育饮食转变，并建立了一组考虑到这些饮食转变的鱼类摄食 guild 结构。每个物种被分为若干大小类别。通过 UPGMA 聚类分析，利用这十个物种整个群体中种内和种间大小类别对之间的饮食重叠值，构建了饮食相似性的系统树图。通过应用自展程序客观地确定了 guild 的数量及其成员。识别出四个“个体发育”摄食 guild（OFG），每个都由物种的大小类别组成。大多数物种属于不止一个 guild。有趣的是，当将自展程序应用于基于“分类学”或完整物种饮食的系统树图时，只发现了一个显著的 guild。这些个体发育饮食转变对种间相互作用的影响很大，因为每种鱼类共享资源的物种身份在其生命过程中会发生变化。分类学物种用于研究这个组合中潜在竞争相互作用的有用性大大降低。
