Analyses of diet preference of larval orange-spotted grouper (Epinephelus coioides) grown under inorganic fertilization method using next-generation sequencing

Abstract Orange-spotted grouper (Epinephelus coioides) is one of the most important aquaculture species in tropical and subtropical Asia. Traditionally, rotifer are fed to the larvae after they hatched. However, larval survival rate has been very low, and prey of suitable size during the first week after hatching is a major constraint. In this study, we raised grouper larvae by using an inorganic fertilization method to produce natural assemblages of phytoplankton and zooplankton, and compared it to a traditional rotifer-fed group. The results showed higher larval survival rate in inorganic fertilization group, albeit not significantly different due to high variation. Using next-generation sequencing to examine the fish stomach content from inorganic fertilization group, we found that copepods and choanoflagellates were actively consumed, whereas rotifers were not. The results imply that the inorganic fertilization method can produce desirable forage species for the grouper larvae, and it can be an alternative way in grouper larviculture worldwide.