Feeding, growth and bioluminescence of the heterotrophic dinoflagellate Protoperidinium huberi
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- Buskey, E.J., Coulter, C.J. & Brown, S.L. Marine Biology (1994) 121: 373. doi:10.1007/BF00346747
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Feeding, growth and bioluminescence of the thecate heterotrophic dinoflagellate Protoperidinium huberi were measured as a function of food concentration for laboratory cultures grown on the diatom Ditylum brightwellii. Ingestion of food increased with food concentration. Maximum ingestion rates were measured at food concentrations of ∼600 μg C l-1 and were ∼0.7 μg C individual-1 h-1 (1.8 D. brightwelli cells individual-1 h-1). Clearance rates decreased asymptotically with increasing food concentration. Maximum clearance rates at low food concentration were ca. 23 μl ind-1 h-1, which corresponds to a volume-specific clearance rate of 5.9x105 h-1. Cell size of P huberi was highly variable, with a mean diameter of 42 μm, but no clear relationship between cell size and food concentration was evident. Specific growth rates increased with food concentration until maximum growth rates of ∼0.7 d-1 were reached at a food concentration of 400 μg C l-1 (∼1000 cells ml-1). Food concentrations as low as 10 μg C l-1 of D. brightwellii (∼25 cells ml-1) were able to support growth of P. huberi. The bioluminescence of P. huberi varied with its nutritional condition and growth rate. Cells held without food lost their bioluminescence capacity in a matter of days. P. huberi raised at different food concentrations showed increased bioluminescence capacity, up to food concentration that supported maximum growth rates. The bioluminescence of P. huberi varied over a diel cycle, and these rhythmic changes persisted during 48 h of continuous darkness, indicating that the rhythm was under endogenous control.