APPARENT ASSIMILATION EFFICIENCY IN ARTEMIA RELATED TO BODY-SIZE AND INGESTION RATE

Using marine Chlamydomonas as food (5 pg N/cell), the apparent assimil ation efficiency in the bisexual brine shrimp Artemia franciscana was estimated in terms of nitrogen in order to assist production. The appa rent assimilation efficiency was defined as the ratio of food required for a given growth to the ingested food. Using the previously reporte d data on the growth, daily ration, maintenance ration and food conver sion factors (in seawater at ca. 28-degrees-C), the assimilation effic iency was estimated. The regression of efficiency vs. body size and da ily ration was presented in the range where the efficiency is less tha n 100%. This regression showed that the amount of apparently assimilat ed food decreased with increase in feeding rate above a certain level and gave the reason for decrease in growth speed at higher daily ratio n. The error in the estimation of efficiency was also discussed.