The two most prominent types of plankton in the ocean are zooplankton, which are tiny animal organisms, and phytoplankton, which are plantlike. (Other forms of plankton include bacterial and fungal.

Plankton are mostly microscopic algae and animals found throughout Earth's oceans, seas and lakes, although a few species are visible to humans. Unlike fish, plankton can't swim against the current.

Image caption, This is one type of plankton viewed through a microscope. In fact, many scientists believe that these tiny plants and animals are amongst the most important in our seas. They may ...

Zooplankton are one of the most diverse and abundant groups of organisms on Earth and they play an essential role in the marine food chain. Unable to photosynthesise, as phytoplankton do ...