The 1983 die-off of the long-spined sea urchin Diadema antillarum was linked to dramatic increases in macroalgal biomass and abundance on Caribbean coral reefs. D. antillarum densities have only recently begun to recover, and on some reefs this has led to a decrease in algae and an increase in coral recruits. Given the historic importance of this herbivore and the patchiness of its distribution on modern Caribbean reefs, a better understanding of its feeding preferences for different macroalgae is fundamental to reef ecology and management. This study investigated the feeding preferences of D. antillarum for different macroalgae and benthic cyanobacteria that were most common at our study sites on reefs of the U.S. Virgin Islands, although most of these algae occur throughout the Caribbean. Many of these algae are chemically rich, and some are known to be chemically defended against generalist grazers. Previous studies have suggested that D. antillarum has a greater capacity than herbivorous fishes and other herbivores to consume chemically defended algae. However, in this series of experiments, D. antillarum was more selective than expected in its food choices and avoided eating some macroalgae and cyanobacteria commonly found on shallow reefs of the U.S. Virgin Islands. Types of algae and their chemical extracts that deterred feeding include common brown algae (Dictyota and Lobophora spp.) and cyanobacteria (Dichothrix sp.). These feeding preferences have implications for coral reef ecosystems because some macroalgae and cyanobacteria can have negative effects on the survival of other organisms on reefs, including corals.

1983 年长刺海胆Diadema antillarum 的死亡与加勒比珊瑚礁上大型藻类生物量和丰度的急剧增加有关。D. antillarum 的密度最近才开始恢复，在一些珊瑚礁上，这导致藻类减少和珊瑚新兵增加。鉴于这种食草动物的历史重要性及其在现代加勒比珊瑚礁上分布的不均匀性，更好地了解其对不同大型藻类的摄食偏好是珊瑚礁生态和管理的基础。本研究调查了D. antillarum的取食偏好对于不同的大型藻类和底栖蓝藻，它们在我们在美属维尔京群岛珊瑚礁上的研究地点最常见，尽管这些藻类中的大多数都出现在整个加勒比地区。这些藻类中的许多都富含化学物质，并且已知一些藻类可以通过化学方法抵御多面食草动物。先前的研究表明，D. antillarum比食草鱼类和其他食草动物具有更大的消耗化学防御藻类的能力。然而，在这一系列实验中，D. antillarum在其食物选择上比预期更具选择性，并避免食用一些常见于美属维尔京群岛浅礁的大型藻类和蓝藻。阻止进食的藻类及其化学提取物的类型包括常见的褐藻（Dictyota和Lobophora spp.）和蓝细菌（Dichothrix sp.）。这些进食偏好对珊瑚礁生态系统有影响，因为一些大型藻类和蓝藻会对珊瑚礁上其他生物的生存产生负面影响，包括珊瑚。