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