Heteropneustes fossilis
were subjected to
41.89 mg L
-1 of azadirachtin for short-term exposure (96 h)
and 10.47 mg L
-1 of azadirachtin for long-term exposure
(28 days). The fishwere killed on 24, 48, 72 and 96 h in short-term
and 7, 14, 21 and 28 days in long-term experiment.
Corpuscles of Stannius (CS) were fixed on these time intervals.
CS remain unchanged till 72 h in short-termazadirachtin
exposure. Accumulation of granules has been noticed in the
aldehyde fuchsin (AF)-positive cells at 96 h. The nuclear
volume of these cells remains unchanged. The AF-negative
cells of CS of azadirachtin-exposed fish exhibit a slight
increase in their nuclear volume after 96 h. In long-term
exposure, the CS remain unchanged up to day 14. Increased
granulation in the AF-positive cells has been noticed following
21-day exposure. Moreover, the nuclear volumes of these
cells show a significant decrease. Heavy accumulation of AFpositive
granules and few degenerating cells are also noticed
at 28 day in azadirachtin-exposed
H. fossilis.