Mercury is used in various industrial. Part of
Mercury's
industrial waste is discharged into the
environment,
rivers and their tributaries, thus contaminating aquatic
animals.
Aim:
to evaluate
Mercury-induced behavioral changes in
Zebrafish (
Danio rerio) by the
analysis of
locomotor activity and
parameters related to neurotoxicity and to verify whether ultra-diluted substances can decrease neurobehavioral effects and toxic.
Methodology:
The
fishes were
separated into 4
monitoring aquariums with 8
fishes each, with
temperature,
pH controlled, until the
time of the toxicological experiments. 0.5 mL of
Mercury 6cH, 30cH and
distilled water (positive control) were added per liter of
water in each aquarium containing 6 liters of
water, then 3 mL of medication per aquarium, the
white control received no medication and the toxic agent. After 1 hour the
drugs were added, toxic
mercury (200 µg/L), 4 mL per aquarium was added and remained so for 24 hours. All the experiment was run in blind, and the
drugs identified by
codes. The
animals were subjected to
behavioral tests (Open Field-
locomotion; Vertical Open Field for neurotoxicity evaluation and
Light and Dark Test), and each stage was recorded for later evaluation of
movements and neurobehavioral changes.
ANOVA was performed, followed by Tukey test, with p <0.05.
Results:
Mercury produced an anxiogenic effect in
animals that were submitted to it without medication. In the vertical open field, there was an increase in erratic
movements (1.25 ± 1.0) and tremors (0.87 ± 0.35) compared to the control (0.12 ± 0.35 and 0.25 ± 0.46 respectively), proving the toxic effect.
Fishes which received the medication at 6 cH and 30 ch showed tremors and erratic
movements similar to control.
Conclusion:
200 µg/L
mercury in
water can cause neurobehavioral disturbances in
fishes, and
animals receiving Mercurius6 cH and 30 cH ultra-diluted
drug did not show neurotoxicity.