|Growth and carbon uptake by natural populations of oceanic dinoflagellates Pyrocystis noctiluca and Pyrocystis fusiformis|Rivkin, R.B.; Swift, E.; Biggley, W.H.; Voytek, M.A. (1984). Growth and carbon uptake by natural populations of oceanic dinoflagellates Pyrocystis noctiluca and Pyrocystis fusiformis. Deep-Sea Res. Pt. A: Oceanogr. Res. Pap.A: Oceanogr. Res. Pap 31(4): 353-367. hdl.handle.net/10.1016/0198-0149(84)90089-x
In: Deep Sea Research, Part A. Oceanographic Research Papers. Pergamon Press: Oxford. ISSN 0198-0149, more
Pyrocystis fusiformis C.W.Thomson, 1876 [WoRMS]; Pyrocystis noctiluca Murray ex Haeckel, 1890 [WoRMS]; Marine
|Authors|| || Top |
- Rivkin, R.B.
- Swift, E.
- Biggley, W.H.
- Voytek, M.A.
Vertical profiles of species-specific carbon uptake rates were determined for Pyrocystis sp. collected from net tows in the Gulf Stream and Sargasso Sea and incubated for 1 to 2 h in situ. Rates of cell division (estimated from the frequency of dividing cells) and cellular Chl a, carbon and nitrogen contents were also measured. The in situ rates of cell division (0.085 to 0.116 d-1), the maximum rates of photosynthesis (1.7 to 1.9 ng carbon cell-1 h-1), and the molar C: N ratio (10) of isolated cells were similar to those observed in exponentially growing cultures data suggest that Pyrocystis, although contributing only ca. 1% to community primary production, was neither nutrient nor light limited in situ. Cell division rates were relatively constant throughout the euphotic zone. In contrast, rates of photosynthesis and carbon-specific growth declined by an order of magnitude between the mixed layer and the bottom of the euphotic zone. When integrated over the euphotic zone, rates of carbon-specific growth and cell division were similar, 0.122 and 0.116 d-1, respectively, at the most nutrient-poor station, and 0.098 and 0.085 d-1, respectively, at the most nutrient-poor station. We suggest that during its migration between the mixed layer and the base of the euphotic zone, Pyrocystis sp. assimilates carbon in excess of its immediate metabolic requirements near the surface and catabolizes the stored carbon at greater depths, thus maintaining a relatively constant division rate at all depths within the euphotic zone.