The grouper, Epinephelus coioides, larvae were reared in outdoor tanks with nauplii of copepods and/or rotifers, Brachionus rotundiformis as food. Nauplii propagated in tanks consisted mainly of Pseudodiaptomus annandalei and Acartia tsuensis. Gut content was examined for a total of 953 larvae sampled from day 3 to day 10 (day of hatching being day 0) . Grouper larvae successfully started feeding on early stage nauplii even if their abundance was as low as ca. 100 ind./l and showed better survival and growth thereafter compared to those fed with rotifers only. Feeding incidence reached 100% on day 4 when nauplii were available and only on day 9 when rotifers were given alone. Selective feeding ability of larvae seemed to start from day 4 and the larvae thereafter preferred to feed on medium- and large-size nauplii than rotifers. Coastal calanoid copepods of the genera Pseudodiaptomus and Acartia could be reproduced in tanks and their nauplii can be used as food for marine fish larval rearing
