In the present study area total number of 100 species of Zooplanktons was recorded in the Adirampattinam mangrove water and Adirampattinam coastal waters. The percentage composition of each group of Zooplankton in mangrove water (St.I) was in decreasing order - Rotifers 18% > Copepoda 18% > Larva form 16% Foraminifera 10% > Ostracods 8% > Cladocera 7% > Protozoa 7% > Insects 5% > Coelentrate 4% > Cyclopodia 4% > and Herpatcticoidea 3%. The percentage composition of each group of Zooplankton in coastal water (Station II) was in decreasing orders Rotifers 22% > Copepoda 20% > Larva form 15% > Foraminifera 9% > Protozoa 8% > Cladocera 7% > Ostracods 7% > Insects 5% > Coelentrate 3% > Cyclopodia 2% > Herpatcticoidea 2%. Overall average percentage composition of each group of Zooplankton in both stations (St.I and St.II) in the decreasing order in Rotifers 20%> Copepoda 19% > Larva form 15% > Foraminifera 10% > Ostracods 8% > Protozoa 7% > Cladocera 7% > Insects 5% > Coelentrate 4% > Cyclopodia 3% > Herpatcticoidea 2%. The Zooplankton percentage composition exhibited very high in mangrove water (Station I) and very low in coastal water (Station II), because of the high productivity due to mangrove litter fall that supports a host of dexterous feeding animals such as Amphiods, Harpacticoids larvae and fishes.
