plankton

This term describes a diverse collective of aquatic organisms that lack the swimming strength to move against a current. It evokes an image of a vast, invisible biological soup that forms the foundation of the marine food web, shifting the focus from individual creatures to a mass of drifting biomass.

Grammatically, this noun is treated as an uncountable mass noun. It does not have a plural form and cannot be counted with numbers; instead, it requires partitive constructions such as a colony of plankton or a sample of plankton to specify quantity.