Zooplankton are tiny animals that drift in the water column of oceans, seas, and lakes. They are a vital part of the marine food web, serving as a food source for larger animals like fish, whales, and seabirds.

Here's a breakdown of what zooplankton are:

* Heterotrophic: They cannot produce their own food and must consume other organisms to survive.

* Planktonic: They live in the water column and are unable to swim against currents.

* Diverse: Zooplankton include a wide range of creatures, from microscopic crustaceans to jellyfish and even some small fish larvae.

Some common examples of zooplankton include:

* Copepods: Tiny crustaceans that are a major food source for many fish.

* Krill: Small shrimp-like creatures that are important food for whales and other marine animals.

* Jellyfish: Gelatinous animals with tentacles that capture prey.

* Foraminifera: Single-celled organisms with shells that can be found in ocean sediments.

Let me know if you have any other questions about zooplankton!