S. No Prey items Numbers (%) Volume (%) Frequency of occurance(F) Index of Relative Importance (N+V)F = IRI
1 Crustaceans 16.4 21.5 5.88 142.82
2 Fish 13.5 14.6 9.56 153.076
3 Amphipods 4.8 5.2 11 62.00
4 Isopods 6.3 3.1 5.88 24.528
5 Polychaetes 4.7 2.7 8.82 28.514
6 Nematodes 5.9 3.2 7.35 29.42
7 Phytoplankton 5.7 1.7 4.41 13.197
8 Zooplankton 7.1 6.3 5.15 39.545
9 Gastropods 2.5 1.8 5.88 13.084
10 Bivalves 4.1 2.3 3.68 12.564
11 Sand 3.8 6.4 7.35 50.84
12 Detritus 6.5 8.5 10.3 94.05
13 Miscellaneous 11.5 16.4 8.09 144.176
14 Supplementary feeds 7.2 6.3 6.62 48.906
Table 7: The Index of Relative Importance (IRI) of the prey items of shrimp P. monodon during May-2012.