Geographical Variation in the Effects of Brown Algal Secondary Metabolites on Temperate Marine Herbivores

本研究建立在先前发现的基础上，即温带东北和西南太平洋地区海带类植物产生的次生代谢物存在定性和定量差异。这项研究的目的是：1)进一步记录加利福尼亚和新西兰的大型褐藻中次生化学物质的含量和种类的变化；2)确定选定的海洋植食性无脊椎动物对这些化合物的行为和长期反应。将从这两个地区进行广泛收集，以记录常见褐藻物种中多酚类和亲脂类化合物浓度的变化；在个体之间和种内的组织之间；随着时间的推移，在分离的植物中。将通过测量消耗率的变化来测试来自这两个地区的普通海胆和蜗牛的进食偏好对这些次级化合物的影响。次生代谢物对各种植食性无脊椎动物的生理影响将通过测量吸收效率、生长速率和性腺发育来评估，其中次生代谢物的种类和水平是不同的。假设海藻和食用海藻的动物之间的相互作用在两个重要方面有所不同：1)新西兰海藻的化学防御的数量和多样性将大于加利福尼亚的藻类；2)新西兰的食藻动物比加利福尼亚的无脊椎动物更能耐受多酚类物质。总的来说，在生物地理尺度上，从温带岩石海岸主要的初级生产者藻类到消耗它们的无脊椎动物的能量转移的调节机制预计会有很大的变化。

This research builds on previous findings that qualitative and quantitative differences exist in the secondary metabolites produced by kelp-like plants between the temperate northeast and southwest Pacific regions. The purpose of the research is to: 1) further document variation in the levels and kinds of secondary chemicals among large brown algae from California and New Zealand, and 2) determine behavioral and long term responses of selected marine plant-eating invertebrates to these compounds. Extensive collections will be made from both areas to document variation in concentrations of polyphenolic and lipophilic compounds among the common brown algal species; among individuals and tissues within species; and through time in detached plants. Feeding preferences of common sea urchins and snails from both regions will be tested for the effects of these secondary compounds by measuring variation in consumption rate. Physiological influences of secondary metabolites on various plant-eating invertebrates will be evaluated by measuring absorption efficiencies, growth rates, and gonadal development among experimental treatments in which the kinds and levels of secondary metabolites are varied. Hypothetically interactions between algae and the animals which consume them will differ among these regions in two important ways: 1) the amount and diversity of chemical defenses in New Zealand algae will be greater than in California species; and 2) the algae eaters in New Zealand will be more tolerant of polyphenolics than will similar algal consuming invertebrates from California. Overall, the mechanisms which mediate transfer of energy from the algae which are the dominant primary producers on temperate rocky shores to the invertebrates which consume them are predicted to vary greatly on a biogeographical scale.