Plankton classification

Classification of the plankton as a whole is often made on the basis of size (Fig. 1.9). The ultrananoplankton (or picoplankton) is composed almost entirely of bacteria, the nanoplankton of algae (phytoplankton), and the macro- and megaplankton of animals (zooplankton), mainly invertebrates. 

Fig. 1. 9 Size classification of plankton (the 0.2 to 2 im size range is often termed the picoplankton).

Reynolds, C.S., Huszar, V., Kiuk. C., NaselU-Flores, L. and Melo. S. (2002) Towards a functional classification of the freshwater phytoplankton. Journal of Plankton Research. 24. pp. 17-428. 

One immediate result of such classification of bacterial states according to availability of nutrients is that, as in almost all experiments that are being carried out under laboratory conditions, the bacteria have all the required nutrients around them, and they may be inclined to prefer planktonic growth over sessile conditions, whereas a great majority of MIC problems come from sessile bacteria, not planktonic ones. This can call into question the reliability of such experiments, especially if one bears in mind the direct relationship between corrosion rate changes and sessile microorganism growth. ... 

Martinovic-Vitanovic V, Kalafatic V (1990) Classification of some reservoirs in SR Serbia (SFRJ Yugoslavia) based on analysis of plankton species as indicators of trophic conditions. Arch Hydrobiol Beih Ergebn Limnol 33 831-837... 

The Centrales are generally planktonic because the discoid structure makes it possible to increase the surface area/volume ratio, and thus to increase buoyancy in fresh or salty water. Pennales are generally benthic because their lengthened structure does not permit this buoyancy. Although diatoms are all unicellular, filamentous colonial forms also exist, the length of which can attain 2 mm. A simplified classification of the marine diatoms is presented in Table 9.1 (the main genera for which research into their metabolites has been conducted are shown in bold type). 

---