CULTURE OF CYCLOPOID COPEPOD METACYCLOPS GRACILIS FED ON SCENEDESMUS QUADRICAUDA AT DIFFERENT OXYGEN CONCENTRATIONS

Abstract

One of the essential factors in zooplankton culture is dissolved oxygen (DO), especially copepods. This is because of DO effects on their growth and reproductive parameters. Effects of different DO concentrations on growth and production of cyclopoid copepod Metacyclops gracilis fed on green algae Scenedesmus quadricauda were investigated in laboratory conditions. Experiment treatments were 2, 3, 4, and 6mg/l of DO. Results showed that mean total production (nauplii+copepodids+adults) of M. gracilis were 3666.7, 3133.3, 3600.0 and 3733.3ind./1 at 2, 3, 4, and 6mg/1 DO, respectively. While total nauplii production was 1533.3, 2000.0, 2466.7 and 2800.0ind./l, and copepodids were 1266.7, 666.7, 600.0, and 600.0ind./l, respectively. The specific growth rates (SGR) of M. gracilis were 0.088, 0.082, 0.061 and 0.081/day at 2, 3, 4, and 6mg/1 DO, respectively. This study showed that M. gracilis can grow and produce at different concentrations of DO, but at 4 and 6mg/1 DO nauplii stage and at 2 and 3mg/1 DO adults stage significantly increased in population. This species could be used as live food for fish larval rearing in aquaculture industry.

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