goldfish carassius auratus were subjected to either formalin (250 ppm) or nacl (10 ppt), over a 0.5-h period followed by 24-h freshwater exposure. serum biochemistry was monitored before exposure (0), immediately after (0.5) plus 3 and 24 h after exposure. results showed that both formalin and nacl treatments caused rapid increase in cortisol with a peak at 3 h, which did not recover until 24 h...