Collaborative Research: Feeding Selectivity and Strategies on Marine Bivalves

Levinton/Ward本建议继续开展研究双壳类软体动物对活的和碎屑的复杂混合物中颗粒的选择性机制的工作，以便(1)开发一种使用视频内窥镜对Pallial腔内的颗粒进行采样并用流式细胞仪对这些样品进行分析的定量方法；(2)在不同的双壳类取食类型之间进行比较研究；(3)确定双壳类的限制性加工步骤(如对颗粒进行掌部分选，通过肠道处理颗粒)，以形成双壳类颗粒在Pallial腔的不同区域内的转移和处理模型。这些结果反过来可以用来构建双壳类摄食和颗粒加工的综合模型，最终可以与Seston动力学的海岸生态系统模型联系起来。我们以前的研究结果表明，流式细胞仪和视频内窥镜的结合是研究(A)颗粒加工速率和颗粒选择性程度和(B)机理的有力工具。在牡蛎和贻贝中，我们可以证明对低营养价值的颗粒具有很强的选择性，以及颗粒质量对加工速度的影响。这种新的方法给了我们一个很好的测试，我们只是触及了饲养功能生态中的重要问题的皮毛，以及可能被研究的对海岸系统的影响。

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.