Plankton (Sapphirina sp.)is an invertebrate copepod marine (saltwater) or freshwater animal. An invertebrate is soft-bodied, without bones. 

The King of the Plankton is the Sapphirina genus, one of the most abundant zooplankton. It looks like a transparent (see-through) insect, with an oval body, several segments, two antenna, simple eyes, and small tail-like segments. 

It is microscopic. However, the jellyfish is actually a plankton too, so plankton can be various sizes. Plankton is named according to its size: for example, megaplankton is over 20 centimetres (8 inches) long – i.e. jellyfish. Bacterioplankton is tiny bacterium; mycoplankton is a fungus; phytoplankton is surface algae and the diatom; and zooplankton is a microscopic crustacean.

Plankton live in oceans, rivers, ponds, and lakes and drift with the currents. It cannot swim. It can live in a range of saltwater and freshwater habitats. 

Fish, whales, and aquatic animals eat plankton. But what do plankton eat? Plankton eat diatoms, which are even smaller planktons. 

Photographer: Martina Nicolls

Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM