Plankton

People want to know what is plankton. I said, I don't know, but every people who meet in the fishes grocery ask this because plankton become the meal of Red Crystal Shrimp, a decorative shrimp animal, that currently in trendy.

Then I search through google search engine and get the answer as follows:
Actually plankton is friend of Sponbob:

 

The scientist explanation about plankton as follows:
Plankton (singular plankter) are any organisms that live in the water column and are incapable of swimming against a current. They provide a crucial source of food to many large aquatic organisms, such as fish and whales.

These organisms include drifting animals, protists, archaea, algae, or bacteria that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification.

Though many planktic species are microscopic in size, plankton includes organisms covering a wide range of sizes, including large organisms such as jellyfish.