Feeding Behaviour and Digestion Pattern in Stylonychia mytilusEhrenberg

Abstract

Summary Stylonychia mytilus is a phagotrophic feeder with a strong discriminating sense of food selection. The inorganic and non-nutrient organic particles are rejected while as the organic nutrientrich particles are readily ingested. Among a variety of live food materials also, there is a preferential acceptance of specific prey organisms. The rate of uptake of food material is high in the initial phases of feeding. The log phase cells feed at a higher rate than the stationary phase cells. Controlled feeding experiments show that total digestion time increases proportionately with the number of ingested food organisms, though all the prey organisms become acid phosphatase positive within minutes of their ingestion. Experiments with cycloheximide inhibition show that Stylonychia possess a reserve pool of digestive enzymes sufficient to catabolize about 25 food organisms. The reservoir of digestive enzymes shows a slow turnover rate. Proteins other than lysosomal enzymes are involved in the process of ingestion; such proteins show countinuous turnover.