other plankton. The study of plankton is termed planktology and a planktonic individual is referred to as a plankter. The adjective planktonic is widely used in both the scientific and popular literature, and is a generally accepted term. However, from the standpoint of prescriptive grammar, the less-commonly used planktic is more strictly the correct adjective. When deriving English words from their Greek or Latin roots, the gender-specific ending (in this case, "-on" which indicates the word is neuter) is normally dropped, using only the root of the word in the derivation. Trophic groups Plankton are primarily divided into broad functional (or trophic level) groups: Phytoplankton (from Greek phyton, or plant), are autotrophic prokaryotic or eukaryotic algae that live near the water surface where there is sufficient light to support photosynthesis. Among the more important groups are the diatoms, cyanobacteria, dinoflagellates and coccolithophores. Zooplankton (from Greek zoon, or animal), are small protozoans or metazoans (e.g. crustaceans and other animals) that feed on other plankton. Some of the eggs and larvae of larger nektonic animals, such as fish, crustaceans, and annelids, are included here. Mycoplankton include fungi and fungus-like organisms, which, like bacterioplankton, are also significant in remineralisation and nutrient cycling. Bacterioplankton include bacteria and archaea, which play an important role in remineralising organic material down the water column (note that prokaryotic phytoplankton are also bacterioplankton). Virioplankton are viruses. Viruses are more abundant in the plankton than bacteria and archaea, though much smaller. Mixoplankton Mixotrophs. Plankton have traditionally been categorized as producer, consumer and recycler groups, but some plankton are able to benefit from more than just one trophic level. In this mixed trophic strategy—known as mixotrophy—organisms act as both producers and consumers, either at the same time or switching between modes of nutrition in response to ambient conditions. This makes it possible to use photosynthesis for growth when nutrients and light are abundant, but switching to eat phytoplankton, zooplankton or each other when growing conditions are poor. Mixotrophs are divided into two groups; constitutive mixotrophs, CMs, which are able to perform photosynthesis on their own, and non-constitutive mixotrophs, NCMs, which use phagocytosis to engulf phototrophic prey that are either kept alive inside the host cell which benefit from its photosynthesis, or they digest their prey except for the plastids which continues to perform photosynthesis (kleptoplasty). Recognition of the importance of mixotrophy as an ecological strategy is increasing, as well as the