An investigation of the unicellular alga, Rhinomonas reticulata var. reticulata for feeding the rotifer Brachionus plicatilis in a marine hatchery  <B>An investigation of the unicellular alga, Rhinomonas reticulata var. reticulata for feeding the rotifer Brachionus plicatilis in a marine hatchery</B><P>A. Vassallo</B><I><P> EuroMediterranean Centre on Insular Coastal Dynamics, Foundation for International Studies, University of Malta, Valletta, Malta</I><P> Abstract<P> Feeding trials were conducted in order to observe the effect of Rhinomonas reticulata var. reticulata, Novarino 1991, fed solely or in combination with baker's yeast (Saccharomyces cerevisiae) on the population development of the rotifer Brachionus plicatilis Mueller under laboratory conditions; control diets of Nannochloropsis oculata (Droop) Hibberd and N. oculata and yeast were used. Growth rates and fecundity parameters were studied for fifteen days. Rotifers fed on R. reticulata, alone or with yeast gave good performances with the most promising results in all the parameters studied. Growth rates were not significantly different for the diets tested but the highest rotifer densities were attained by the population fed exclusively R. reticulata (>800 ind/ml). The interaction between the diet given and the age of the culture was found to affect population fecundity in a significant way.<P>