S. No Prey items Numbers (%) Volume (%) Frequency of occurance(F) Index of Relative Importance (N+V)F = IRI
1 Crustaceans 15.3 19.8 4.43 103.014
2 Fish 12.7 16.3 7.59 136.417
3 Amphipods 3.6 5.8 8.86 54.988
4 Isopods 4.3 4.3 6.96 34.228
5 Polychaetes 3.5 2.6 6.33 19.958
6 Nematodes 4.2 1.9 9.49 22.231
7 Phytoplankton 5.4 2.3 7.59 22.857
8 Zooplankton 6.2 3.2 8.86 34.552
9 Gastropods 2.8 1.3 6.33 11.029
10 Bivalves 5.2 4.8 5.06 29.488
11 Sand 6.9 5.2 5.7 36.54
12 Detritus 8.1 12.6 8.86 119.736
13 Miscellaneous 13.5 14.3 7.59 122.037
14 Supplementary feeds 8.3 5.6 6.33 43.748
Table 6: The Index of Relative Importance (IRI) of the prey items of shrimp P. monodon during April-2012.