<p><span style="font-size:14px"><span style="font-family:Arial,Helvetica,sans-serif">Total heterotrophic bacterial (THB) load of detritus fin and shell fishes collected from mangrove environment were investigated. The collected fish and prawn samples were subjected to the microbiological study. The THB load was higher in milk fish (<em>Chanos chanos</em>) (2.24 x 10⁵ CFU/g) followed by Indian white prawn (<em>Fenneropenaeus indicus</em>) (3.16 x 10⁵ CFU/g) than the <em>Liza parsia </em>(1.90 x 10⁵CFU/g) and<em> Penaeus monodon</em> (1.88 x 10⁵ CFU/g). A total of 355 bacterial strains were isolated and identified, in which 64, 57, 51, 47, 44, 42, 21, 29, 355 strains were belongs to <em>Pseudomonas</em> spp., <em>Aeromonas</em> spp.<em>, Bacillus</em> spp.<em>, Enterobacter</em> spp.<em>, Vibrio </em>spp.<em>, Flavobacterium</em> spp.<em>, Alcaligenes </em>spp. and<em> Acinetobacter</em> spp<em>., </em><em>Pseudomonas </em>spp. and <em>Aeromonas</em> spp., respectively. The present work showed that the <em>Bacillus</em> spp., were higher in the gut of fish and prawn samples studied. This work suggests that these bacteria can be effectively used as supplement in fish/prawn feed for commercial aquaculture or as probiotic to enhance the colonization in fish/prawn gut.</span></span></p>