Department of Animal Ecology and Ecophysiology, Institute for Water and Wetland Research, Faculty of Science, Radboud University, Heyendaalseweg 135, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands.
J Fish Biol. 2009 Oct;75(6):1123-43. doi: 10.1111/j.1095-8649.2009.02303.x.
This study used three different methods to ascertain dietary composition for 21 Chaetodontidae species co-occurring on a single fringing reef in Derawan Island, East Kalimantan, Indonesia. The combination of in situ feeding observations, examination of gut contents and stable-isotope analyses was expected to identify previously unresolved prey items that contribute to dietary separation. In situ feeding observations identified five species that feed predominantly on anthozoans (Chaetodon baronessa, Chaetodon bennetti, Chaetodon lunulatus, Chaetodon punctatofasciatus and Chaetodon speculum). Stable-isotope ratios for these species, as well as for Chaetodon ornatissimus (for which no feeding observations were completed), were very similar and consistent with diets comprising mostly anthozoans. Feeding observations, however, showed that they mostly fed on different coral species, while the identifiable portion of their gut contents showed clear separation based on cryptic dietary components. For example, C. baronessa and C. bennetti appeared to ingest annelid worms during the course of coral feeding, whereas gut contents of C. punctatofasciatus and C. speculum were dominated by crustaceans. In situ feeding observations further identified the following groups: coral-bottom feeders, bottom feeders, sponge feeders and pelagic feeders, feeding on a wide variety of prey items such as Annelida, Crustacea, Cnidaria, Mollusca and macroalgae. Overall, many chaetodontid species had similar reliance on major prey items (e.g. anthozoans or polychaetes) but differed greatly in the minor prey items that they utilized. Partitioning of minor prey items may be important in reducing interspecific competition and facilitating coexistence of chaetodontids on coral reefs.
本研究使用三种不同的方法来确定在印度尼西亚东加里曼丹达拉湾的单个边缘礁上共同出现的 21 种刺盖鱼科鱼类的饮食组成。预计原位摄食观察、检查肠道内容物和稳定同位素分析的结合将确定以前无法解决的有助于饮食分离的猎物。原位摄食观察确定了 5 种主要以珊瑚为主食的物种（巴伦萨刺盖鱼、贝内特刺盖鱼、月斑刺盖鱼、斑点鳍刺盖鱼和金圈刺盖鱼）。这些物种的稳定同位素比值，以及没有完成摄食观察的杂色刺盖鱼，非常相似，并且与主要由珊瑚组成的饮食一致。然而，摄食观察表明它们主要以不同的珊瑚物种为食，而它们的肠道内容物的可识别部分则基于隐藏的饮食成分清楚地区分开来。例如，巴伦萨刺盖鱼和贝内特刺盖鱼似乎在珊瑚摄食过程中摄取环节动物蠕虫，而斑点鳍刺盖鱼和金圈刺盖鱼的肠道内容物则以甲壳类动物为主。原位摄食观察还确定了以下群体：珊瑚底食者、底食者、海绵食者和浮游食者，它们以各种猎物为食，如环节动物、甲壳类动物、刺胞动物、软体动物和大型藻类。总体而言，许多刺盖鱼科鱼类对主要猎物（例如珊瑚或多毛类）的依赖程度相似，但它们利用的次要猎物差异很大。次要猎物的分配可能对减少种间竞争和促进刺盖鱼科鱼类在珊瑚礁上共存很重要。
