Darkness and plankton light.
Plankton appears only during Eddie levels: Midnight Zones. It will emit some light once eaten, and emit light even when alive. They will be eaten by other fish, being considered food. I will swim up, down, to right and left like its a fish. It will also be stunned by jellyfish once it touches them. They first appear in Midnight Zone and last in No Stomach for the Fight, are eaten by cod and pompano and appear 6 times in the game or 1/10th total.