Different larval stages of Penaeus monodon were fed with increasing densities of Tetraselmis sp. to evaluate the relationship between food density, ingestion rates, development and growth of Penaeus monodon larvae. Ingestion showed a saturation response to food density. This served as a basis for determining maximum ingestion rates and incipient limiting levels (ILL), defined as the lowest food density to provide maximum ingestion rates (McMahon and Rigler, 1963). Both ILL and maximum ingestion rate increased as larval stage progressed, with maximum ingestion rate reaching a peak at mysis 3 and declining at postlarva 1. When protozoea 1 and protozoea 2 were given Tetraselmis sp. at levels equal to or above their respective ILL's, rate of development to protozoea 3 was enhanced. Growth rate, in terms of total length, was significantly enhanced in protozoea 3 and mysis 1 if earlier stages were given Tetraselmis sp. at levels equal to or above their respective ILL's.