Explanation

Since there is no penetration of effective light to profundal zone, there are no photosynthetic organisms and hence, consumers depend for their food on limnetic and littoral zones. In littoral zone, the main producers are phytoplanktons, algae and other hydrophytes. In limnetic zone, the main producers are diatonms, cyanobacteria dinoflagellates, Euglenidae and Volvocidae.