No mortality of A. testudineus was observed during the first 24 hours in the lowest concentration i.e
3.125%. This probably is contributed by the fact that A. testudineus is highly robust, thus have higher
capability to tolerate leachate exposure. However, mortalities were recorded after 24 hours in leachate
from closed landfill. This could be contributed by the high concentration of ammoniacal-nitrogen in the
leachate from the closed landfill. Similar observation was noted for the concentration of 4.375% where no
mortality was recorded among fishes exposed to the leachate from the active landfill, while leachate from
the closed landfill killed 40% of the fish in the same concentration. However, number of mortality
increase to 60% and 45% in the active and closed landfill leachate, respectively at 5.00% concentration.
This probably due to the fact that the presence of pollutants in this concentration might be inducing
certain biochemical reactions within the cells of A. testudineus, thus become toxic to the fishes.
At the highest concentration of leachate exposure (5.625%), the number of mortality ranged from
75%-80% for leachate from active and closed landfills. Therefore, the toxicity test indicated that both