No, they are plants, and vary in size from microscopic to sea-weed.
I wonder if you were thinking of the Amoeba, which is a tiny, single-celled animal only just visible to the naked eye?
Whales usually eat Plankton, which is a microscopic algae type thing. Many things eat microscopic animals, I believe herring is one species.
Certain algae is unicellular and microscopic. Multicellular algae can be microscopic, but often are not. Seaweed is an example of algae that is a single multicellular organism and not microscopic.
The microscopic algae are unicellular, colonial and filamentous forms of organisms.
It is a microscopic algae.
The general term for a small microscopic water plant is algae or micro algae.
Algae
Gastrotrichs are microscopic marine animals that have worm shaped bodies. They eat decaying matter, bacteria, algae, as well as protists.
Gastrotrichs are microscopic marine animals that have worm shaped bodies. They eat decaying matter, bacteria, algae, as well as protists.
Microscopic Algae live in coral reefs
Plankton, Zooplankton, Planaria, Algae (Algae are plants, growing in the water.) {Wrong category: This isn't a Gorillas category question: this is a Marine Animals or Marine Plants question, or an Ocean or Water question.}
Seaweed is a type of marine algae that is large and multicellular, while algae refers to a diverse group of photosynthetic organisms that can be found in various aquatic environments. In general, seaweed specifically refers to larger, macroscopic algae, while algae can include both macroscopic and microscopic species.
Algae are protists because they have some of the same organelles. They also are actually called plant like protists. They are still in the protists kingdom though. Protists are microscopic. But, algae is not microscopic. It is confusing but algae is in the Protists Kingdom. Algae also has call walls.