The Great Barrier Reef Library

A comprehensive guide to The Great Barrier Reef


By on May 28, 2018


Protozoa is another Kingdom complete with microscopic animals that bridge the gap between Animals and Plants. They can be found in all habitats from the waterways to the land and make up a large proportion on oceanic Plankton. Whilst Protozoa typically ingest food (like an animal), they are also capable of photosynthesis (like a plant).

Protozoans may feed on Bacteria, or switch to photosynthesis, whilst others are capable of doing both simultaneously. This makes them an important part of the food web. Some are parasitic, whilst others are a vital component of the gut, particularly in Fish.

Most reproduce asexually by binary fission, however, some reproduce sexually through Conjugation. This is where two individuals fuse together in exchange for genetic material.

Certain Protozoans are even capable of surviving in an inactive state, termed a Cyst. This usually occurs when conditions become unfavourable. They cover themselves in a thickened cell wall to protect themselves until they are ready to re-emerge.

Whilst most in this Kingdom live as individuals, some form colonies and some are even capable of switching between the two states.1