Grazing of Protozooplankton Assemblages on Microalgae in the Rearing Water of the Marble Goby, Oxyeleotris marmoratus, During Early Larval Rearing

摘要

We measured the grazing rate of protozooplankton on microalgae, Nannochloropsis sp., in the rearing tank of the marble goby, Oxyeleotris marmoratus, during early larval rearing. The total protozooplankton concentration increased rapidly in the rearingtank 2-3 days after hatching. The daily grazing rate of protozooplankton assemblages on N. oculata ranged from 1.30 x 10~(11) to 1.10 x 10~(12) cells/day, which was equivalent to 16.7% to 79.7% of the total Nannochloropsis sp. abundance/ day. Using a water dilution technique, we estimated that the protozooplankton consumed a maximum of —80% of the Nannochloropsis sp. in a day. This is the first report to provide a quantitative estimate of protozooplankton predation on Nannochloropsis sp. in the rearing water offish larvae.