Abstract:
This study investigated the potential toxic effects of environmentally relevant nitrate concentrations on development, growth,
and mortality of early life stages of common hour-glass tree frog, Polypedates cruciger. Tadpoles from hatchlings through
pre-adult were exposed to environmentally relevant nitrate concentrations detected in Mirissa, Sri Lanka. Newly hatched,
external gill stage, and internal gill stage tadpoles were exposed to potassium nitrate for bioassay tests. No behavioral changes
or abnormalities were observed in control and nitrate-induced group. However, detected environmental nitrate concentration
significantly increased (p < 0.05) the growth of the tadpoles up to 25 days old. Results revealed that newly hatched and
external gill stage was more susceptible to the nitrate pollution than internal gill stage. The results suggest that environmentally
relevant nitrate can cause mortality on the amphibian population in ecosystems associated with agro-pastoral activities
through altering the growth and direct toxicological effects on the survivorship.
