Apparent Assimilation Efficiency in Artemia Related to Body Size and Ingestion Rate

Abstract

Using marine Chlamydomonas as food (5pgN/cell), the apparent assimilation efficiency in the bisexual brine shrimp Artemia franciscana was estimated in terms of nitrogen in order to assist production. The apparent assimilation efficiency was defined as the ratio of food required for a given growth to the ingested food. Using the previously reported data on the growth, daily ration, maintenance ration and food conversion factors (in seawater at ca. 28°C), the assimilation efficiency was estimated. The regression of efficiency vs. body size and daily ration was presented in the range where the efficiency is less than 100%. This regression showed that the amount of apparently assimilated food decreased with increase in feeding rate above a certain level and gave the reason for decrease in growth speed at higher daily ration. The error in the estimation of efficiency was also discussed. © 1994, The Japanese Society of Fisheries Science. All rights reserved.