what animal is plankton from spongebob

Plankton from SpongeBob SquarePants is a subspecies of zooplankton called a copepod. Copepods are tiny sea scavengers that graze on microalgae, scavenge detritus, and serve as food for a myriad of zooplanktivores. Plankton is a deep green planktonic copepod who can fit in the palm of ones hand and has some stubby appendages and one yellow eye. While the fictionalized copepod Plankton exists to contest Mr. Krabs and invoke general mayhem, copepods have a beneficial purpose in real-life marine biology.