Hacrobia are tiny algae, divided into two main groups, the cryptomonads and haptophytes.

They spread throughout the world’s oceans and fresh waters, and are hardly noticed at all, being some of the tiniest life forms on the planet.

They are, however, food for some of the largest lifeforms on the planet, where they are better known as part of the grouping of tiny free floating plants and animals called plankton, the main food source of the enormous blue whale.