The limnetic zone is the open water zone at the top of the water body and consequently receives a good deal of light. This zone contains a variety of fresh water fish with shiny, greyish or silver black scales that help them to merge with the surroundings. Transparent or whitish bodied crustaceans like daphnia, cyclops, small shrimps are also found in this zone. There are different types of floating plants like water hyacinth, wolffia, pistia along with variety of algae.photosynthetic activity is highest. Hope this helps you