Zooplankton:
Zooplankton are tiny free-living animals that float on the surface of water bodies. They are an important component of aquatic ecosystems, serving as a crucial link in the food chain. Here are some key points about zooplankton:

Characteristics:
- Zooplankton are heterotrophic organisms, meaning they rely on other organisms for food.
- They can range in size from microscopic organisms to larger species such as jellyfish.
- Zooplankton exhibit a wide variety of shapes and forms, including crustaceans, rotifers, and larval stages of larger animals.

Ecological importance:
- Zooplankton play a vital role in cycling nutrients in aquatic environments.
- They are an essential food source for many aquatic organisms, including fish, amphibians, and invertebrates.
- Zooplankton populations can indicate the health of an ecosystem, as they are sensitive to changes in water quality and environmental conditions.

Types of zooplankton:
- Holoplankton: These are organisms that spend their entire lives as plankton, such as copepods and krill.
- Meroplankton: These are organisms that only spend part of their lives as plankton, such as the larvae of fish and crustaceans.
In conclusion, zooplankton are an integral part of aquatic ecosystems, serving as a key link in the food chain and playing a crucial role in nutrient cycling. Their presence and abundance can provide valuable insights into the health and dynamics of aquatic environments.

Zooplankton are the tiny animals which lives on the surface of water.