Augmentation of the food supply for oyster larvae via bacterivorous flagellates: possible implications for larval breeding and oyster pond management

Abstract. Examination of the protist plankton in the Espevikpollen oyster pond indicates that the size fraction available to the pelagic larvae of Ostrea edulis L. includes a substantial amount of heterotrophic flagellates. As these kind of flagellates have been shown to be of good food value to veliger larvae of a related species ( Crassostrea gigas Thunberg), the heterotrophic flagellates may be of equal importance as the phototrophic flagellates to the veligers. Therefore, the loop via bacterial production and heterotrophic flagellates may play the same role for Ostrea veligers under pond conditions as this loop plays for the veligers of Crassostrea in certain Japanese aquaculture systems.