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