they are voiced by whom in spongebob squarepants?
Mr. Lawrence and Jill Talley
Plankton and Karen
They are respectively voiced by Mr. Lawrence and Jill Talley. 
is plankton from spongebob a zooplankton or phytoplankton Plankton is an intellectual planktonic copepod and Karen is a waterproof supercomputer.
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Plankton and Karen [SEP] Introduction
Sheldon J. Plankton and Karen Plankton are fictional characters in the Nickelodeon animated television series "SpongeBob SquarePants". They are respectively voiced by Mr. Lawrence and Jill Talley. Their first appearance was in the episode "Plankton!" that premiered on July 31, 1999. They were created and designed by marine biologist and animator Stephen Hillenburg, the creator of the series. Hillenburg named Karen after his wife, Karen Hillenburg. Plankton and Karen are the married owners of the unsuccessful Chum Bucket restaurant. Plankton is an intellectual planktonic copepod and Karen is a waterproof supercomputer. Plankton shares a rivalry with Mr. Krabs, who owns the far more profitable Krusty Krab restaurant and sells a fictional burger called the Krabby Patty.