To scare away predators
To see in the dark
To attract a mate
Just for fun
aquatic (water-living)
plants
drifting or wandering
microscopic
it makes the water saltier.
it kills large predators like sharks.
it makes the water more acidic.
All plankton are microscopic (too small to see without a microscope).
zooplankton
prokaryotes
the ocean
algae
eukaryotes
phytoplankton
Hundreds of cells
Millions of cells
A few dozen cells
Thousands of cells
Zooplankton are tiny animals.