Use of microparticulate markers in examination of rotifer physiology: results and prospects

A short overview is given of some possible ways of using microparticles for the study of rotifer physiology. Besides synthetic microcapsules, some 'na tural' microparticles have been found to be appropriate for this purpose. U sing yeast cells, erythrocytes and erythrocyte ghosts, we were able to exam ine feeding rates, time course and control of nutrient passage, to determin e the pH milieu in the digestive tract and to demonstrate absorptive proces ses. Preliminary results exist of studies on the mechanical efficiency of t he mastax and on the secretion of H+-ions by the intestine. Different types of synthetic microcapsules can be produced for an array of applications. S ome of these are suitable for use with rotifers. Problems exist in producin g them in a suitable uniform size and in loading them efficiently.