Phaeocystis globosa cells

Fig. 7 Modeled abundance of Phaeocystis globosa cells and mortality rates of P. globosa during a mesocosm study (Ruardij et al. 2005). (a) A model run with colonies, and (b) a run without colonies present. Viral lysis is represented by the outline of the black area, microzooplankton grazing by...

Fig. 3.1 Percentage of total Phaeocystis globosa cells within colonies following exposure to chemical cues from grazer-free (open bars) or grazer-containing P. globosa cultures (dark bars). Grazers were (a) natural mixtures of mesozooplankton, (b) the copepod Acartia tonsa, or (c) the ciliate Euplotes sp. From Long et al. (2007) Copyright (2007) National Academy of Sciences, USA...

Dutz J, Koski M (2006) Trophic significance of solitary cells of the prymnesiophyte Phaeocystis globosa depends on cell type. Limnol Oceanogr 51(3) 1230-1238 Dutz J, Klein Breteler WCM, Kramer G (2005) Inhibition... 

Peperzak L, Duin RMN, Colijn F, Gieskes WWC (2000b) Growth and mortality of flagellates and non-flagellate cells of Phaeocystis globosa (Prymnesiophyceae). J Plankton Res 22 107-119... 

Chin WC, Orellana MV, Quesada I, Verdugo P (2004) Secretion in unicellular marine phytoplankton demonstration of regulated exocytosis in Phaeocystis globosa. Plant Cell Physiol 45 535-542... 

Table 8 Microzooplankton grazing on Phaeocystis globosa solitary cells during blooms in the English Channel off northen France May 2003 and April 2004 (JC Nejstgaard, AF Sazhin and LF Artigas unpubl.) ...

Some studies suggest that microzooplankton prefer and perform better on single cells than on colonies. When incubated with a mixture of Phaeocystis globosa single cells and colonies, microzooplankton reduced the single cells to very low abundance, and the grazer population subsequently declined even when colonies were abundant, presumably due to starvation (Jakobsen and Tang 2002). When restricted... 

Fig. 5 Results of a mesocososm study on Phaeocystis globosa bloom dynamics and the ecological role of viruses. The measured data are represented by the symbols and the modeled results are represented by the lines, (a) measured and modeled biomass of P. globosa colonies (solid line and open symbol) and single cells (outline of grey area and...

Fig. 5 Daily specific growth rates of total DMS + DMSPd + DMSPp versus specific cell growth in a variety of axenic Phaeocystis globosa batch cultures under different conditions. Cultures were grown at the same temperature (11°C), but with different salinities, nutrient ratios and/or light conditions. Specific growth rates were calculated per day. Culture growth details are as follows N-sal salinity range from 25 to 50 PSU, nitrogen limited P-sal salinity range from...

Janse I, van Rijssel M, van Hall PJ, Gerwig GJ, Gottschal JC, Prins RA (1996) The storage glucan of Phaeocystis globosa (Prymnesiophyceae) cells. J Phycol 32 382-387... 

This section reviews the different cell types reported for the six Phaeocystis species which are considered here according to their revised taxonomic status as recommended by Baumann et al. (1994), Medlin et al. (1994) and Vaulot et al. (1994). This is particularly relevant for the species globosa, which has long been referred to as pouchetii in the previous literature (e.g., Parke etal. 1971 Kayser 1970 Admiraal and Venek-amp 1986 Veldhuis et al. 1991 Davidson and Marchant 1992a). The seasonal distribution of the different cell types in the natural environment will also be considered in order to assess their role in the life cycle. 

Phaeocystis jahnii colonial cells possess the two short appendages typical of P. globosa and P. antarctica colonial cells, have a size of 6-8.5 pm when five and are irregularly distributed in loose, irregular colonies. Non-motile free-living cells of the same size have also been reported (Zingone et al. 1999). 

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