Improved technology for reliable rapid and high density production of the rotifer, Brachionus plicatilis <B>Improved technology for reliable rapid and high density production of the rotifer, Brachionus plicatilis</B><P> </B><B>M. Kentouri (1,2), P. Divanach (1), A. Hagiatanasiu (1), M.V. Bengoa-Ruigomez (3)</B><I><P> (1) Institute of Marine Biology of Crete - Dept. Aquaculture - Iraklion, Crete, Greece<BR> (2) University of Crete - Dept of Biology - Iraklion, Crete, Greece<BR> (3) University of La Laguna - Tenerife - Spain</I><B><P> Kentouri M. et al. </B>1993. Improved technology for reliable, rapid and high density production of the rotifer, <I>Brachionus plicatilis</I>. Proc. 4th. Natl. Oceanogr. Fish, pp. 418-421.<B><P> INTRODUCTION</B><I><P> Brachionus plicatilis </I>(Muller) is the most important living prey for the feeding of small fish larvae, such as sea bream <I>Sparus aurata </I>(L) in intensive culture. Therefore, its continuous <BR> production is one of great importance for a hatchery manager. Many factors can limit the reproductive rate of this rotifer and/or destroy culture tanks during the production phase. Therefore, all strategies which allow the quick restoration of high densities and volumes of rotifers, with a high reproduction rate, are of particular interest.<P> Two main technologies are used for starting rotifer production. In the first, or batch culture method, rotifers are inoculated at low densities in a plateau phase phytoplankton culture and are harvested when all the algae have been consumed. In the second, chemostat or semicontinuous culture, rotiters are artificially fed at high concentrations in a progressively increasing culture volume until the exploitation phase has been reached. Each of these methods, have a number of advantages and disadvantages.<P> The objective of this article is to describe an improved starting culture technique based on both batch and chemostat strategies which allows the production of 800 litres of 200-400 rolifers/ml<I> </I>over 12-15 days from 2 L Erlen mayor flasks.<I><P> Proceedings of the 4th National Symposium on Oceanography and Fisheries, Rhodes island, (Greece), 26-29 April 1993, pp. 418-421</I><P>