Write the different zones on fresh water eco-system and the adaptations possessed on the animals
Answers
A typical freshwater ecosystem has three zones
1. Littoral zone
This zone is close to the shore and maximum amount of light can penetrate in this zone. A wide variety of phytoplanktons are found in this zone that utilizes light to make food. The animals in this zone i.e. zooplanktons are adapted in such a way that they cling to the plant surface or any other surface and are weak swimmers e.g. Daphnia, rotifers and copepods.
2. Limnetic zone
This zone extends from the littoral zone to the area where light can penetrate. Phytoplanktons like algae, diatoms and algae like flagellates. Animal species that are found in this region are mostly fishes along with zooplanktons adapted to swimming.
3. Profundal zone
It is the deepest zone and no light enters this region. Animals that exist here are adapted to dark e.g. leeches, molluscs, crabs and larvae of some insects.