$(a)$ In many aquatic plants, flowers coming immediately from water are pollinated by wind and insects.

$(b)$ In aquatic plants pollination occurs below water surface then it is called Hypohydrophili e.g. ceratophylum.

$(c)$ In aquatic plants if pollination occurs above surface of water it is called surfaidal water pollination (Apihydrophili) e.g. Valisneria, Spyralis.