REU: Feeding Selectivity and Strategies of Marine Bivalves

本提案继续研究双壳类软体动物在复杂颗粒，活体和碎屑混合物中的选择性机制，以便(1)开发一种使用视频内窥镜对苍白腔内颗粒取样的定量方法，并通过流式细胞术分析这些样品；(2)对不同双壳类取食方式进行比较研究；(3)确定双壳类动物的限制性加工步骤（如：在手掌上对颗粒进行分拣，通过肠道对颗粒进行加工），以形成双壳类动物颗粒在苍白腔各隔室内转移和加工的模型。这些结果可用于构建双壳类动物取食和颗粒加工的综合模型，并最终与海岸生态系统的群落动态模型相关联。我们之前的研究结果表明，流式细胞术和视频内窥镜相结合是研究(a)颗粒处理速率和颗粒选择性程度和(b)颗粒选择性机制的有力工具。我们可以证明牡蛎和贻贝对低营养价值颗粒的强烈选择和颗粒质量对加工速度的影响。这种新方法为我们提供了一种极好的分析方法，我们只触及了可能被检查的喂养功能生态学和对沿海系统影响的重要问题的表面。

Levinton/WardThis proposal continues work initiated to study the mechanisms of bivalve mollusc selectivity among complex mixtures of particles, living and detrital, in order to (1) develop a quantitative method using video endoscopy to sample particles within the pallial cavity and to analyze these samples by flow cytometry; (2) perform comparative studies among different bivalve feeding types; and (3) to identify limiting processing steps of bivalves (e.g., sorting of particles on the palp, processing particles through the gut) in order to form a model of bivalve particle transfer and processing within the various compartments of the pallial cavity. These results, in turn, can be used to construct an integrative model of bivalve feeding and particle processing, which can ultimately be connected to coastal ecosystem models of seston dynamics. Our previous results demonstrate that the combination of flow cytometry and video endoscopy is a powerful tool to study (a) rates of particle processing and the degree and (b) mechanisms of particle selectivity. We could demonstrate in oysters and mussels strong selection against particles of low nutritional value and effects of particle quality on processing rate. This new approach gives us an excellent assay, and we have only scratched the surface of the important problems in feeding functional ecology and effects on coastal systems that may be examined.