Instituto Oceanográfico da Universidade de São Paulo, São Paulo, Brazil.
PLoS One. 2013;8(2):e56107. doi: 10.1371/journal.pone.0056107. Epub 2013 Feb 6.
Not only seasonality but also taxonomic resolution of prey categories has been shown to affect diet studies. We analyzed the stomach contents of three sympatric species, Stellifer rastrifer, S. brasiliensis and S. stellifer, sampled monthly from August 2003 to October 2004 in Caraguatatuba Bay, southeastern Brazil. General characteristics and similarities among their diets were evaluated by considering high taxonomic ranks of all prey groups, and also the lower taxonomic ranks of the main prey groups. Dietary similarity was relatively high among species and low between seasons, and both evaluation criteria gave the equivalent results. The rare items, however, provided information about resource partition, and the species compositions of the most important groups were apparently good indicators of food availability.
不仅季节变化，而且猎物类别的分类学分辨率也会影响饮食研究。我们分析了 2003 年 8 月至 2004 年 10 月在巴西东南部卡瓜塔图巴湾共生的 3 个物种（Stellifer rastrifer、S. brasiliensis 和 S. stellifer）的胃内容物。通过考虑所有猎物组的高分类等级，以及主要猎物组的较低分类等级，评估了它们饮食的一般特征和相似性。在物种之间，饮食相似性相对较高，而在季节之间则较低，这两种评估标准得出了相同的结果。然而，稀有项目提供了资源划分的信息，最重要的群体的物种组成显然是食物供应的良好指标。
