Effect of hydrogen sulphide on the substratum selectivity of shrimp <i>Penaeus indicus</i> (Crustacea/Decapoda)

Abstract

The nature of the substratum is a major factor controlling the distribution of shrimps. Shrimps being benthic spend part of their life embedded in the soil. Any change in the substratum affects the distribution and feed acception which in turn affect their growth and survival. The substratum preference of two size groups (40-45mm and 85-90mm) of Penaeus indicus was studied. Three different substrates viz. clean washed sea sand, mixture df sea sand and powdered clay (3:1) and black hydrogen sulphide containing soil taken from sulphide rich area of shrimp culture ponds were used for the study. Feed acceptance and magnitude of distribution of p. indicus in these substrates were noted. It was observed that both size groups of shrimps showed preference to sandy clay substrates and avoid the substrate with sulphide. While feed acceptance was found significantly low in the hydrogen sulfide containing soil, there was no much difference in the acceptance of feed in other two substrates.