The fish were dissected and different organs of
gill, liver, kidney, intestine and muscle were taken
from the experimental fish as well as control fish
separately and the tissues were washed in double
distilled water and preserved in 10% formalin. Before
analysis, formalin was removed using filter paper
from each tissue. Five hundred mg from each tissue
was placed in separate digestion flask and perchloricnitric
acid mixture in the ratio of 1:2 (v/v) was added
(FAO, 1975). The digestion flasks were gradually
brought and kept at 130°C on hot plate until all
materials dissolved and the digests were diluted with
deionized water. The final acid digested extract was
analysed for Zn concentration using Perkin Elmer
Atomic Absorption Spectrophotometer-3100. The Zn
concentration in tissue was recorded μg g-1 wet tissue.