Predation and the Control of the Sea Urchin Echinometra viridisand Fleshy Algae in the Patch Reefs of Glovers Reef, Belize
Predation and the Control of the Sea Urchin Echinometra viridisand Fleshy Algae in the Patch Reefs of Glovers Reef, Belize
复制标题
伯利兹格洛弗礁斑礁中海胆 Echinometra viridis 和肉藻的捕食和控制
作者：
T. McClanahan
摘要自20世纪80年代中期以来，海胆迪亚德马安蒂拉鲁姆种群的大量减少与许多加勒比海珊瑚礁上肉质藻类丰度的大幅增加有关，尽管还有其他海胆和鳍鱼食草动物。本研究探讨了一种食草动物的生态与D。antillarum，常见且丰富的海胆Echinometra viridis。我研究了鳍鱼和无脊椎动物捕食者在控制E.绿海胆以及这种海胆控制格洛弗礁环礁泻湖的补丁礁上暴露的肉质藻类的能力。我发现这种海胆的主要捕食者是Calamus bajonado（jolhead porgy），Balistes vetula和Canthidermis sufflamen（女王和海洋鱼类），Lachnolaimus maximus（hogfish）和腹足动物，可能是Cassismadagascariensis。E. viridis受捕食作用的限制，这限制了E.到隐蔽的地方，如裂缝。海胆比鳍鱼在实验藻类测定中所占的比例要小。有鳍鱼类的植食性与斑块礁地形复杂性呈正相关。出乎意料的是，E。绿球藻的丰度与肉质藻的丰度呈正相关，而与有鳍鱼类的叮咬频率呈负相关。捕食者限制E.因此，即使在中等高的种群密度（每平方米高达10个）下，也可以减少它们对暴露的肉质藻类的影响。由于珊瑚礁的净底栖初级生产力与暴露表面的食草动物关系最为密切，因此E. viridis不能维持与D.安替拉鲁姆
ABSTRACT The massive reduction in sea urchin Diadema antillarum populations since the mid-1980s has been associated with large increases in the abundance of fleshy algae on many Caribbean reefs despite the availability of other sea urchin and finfish grazers. This study examined the ecology of a grazer living sympatrically with D. antillarum, the common and abundant sea urchin Echinometra viridis. I examined the role that finfish and invertebrate predators play in controlling the distribution of E. viridis as well as the ability of this sea urchin to control exposed fleshy algae on the patch reefs of the Glovers Reef Atoll lagoon. I found that the major predators of this sea urchin were Calamus bajonado (jolthead porgy), Balistes vetula and Canthidermis sufflamen (queen and ocean triggerfish), Lachnolaimus maximus (hogfish), and a gastropod, probably Cassismadagascariensis. The abundance of E. viridis is constrained by predation, which restricts E. viridis to cryptic locations, such as crevices. Sea urchins bit a smaller percentage of experimental algal assays than finfish. Finfish herbivory was associated positively with patch reef topographic complexity. Unexpectedly, E. viridis abundance was positively correlated with fleshy algal abundance, but negatively correlated with the frequency of finfish bites. Predators restrict E. viridis to crevices and therefore reduce their influence on exposed fleshy algae, even at moderately high population densities (up to 10 per square meter). Since net benthic primary production of coral reefs is most strongly associated with herbivory on exposed surfaces, it would appear that E. viridis is unable to maintain the same production as reefs dominated by D. antillarum.