Goldfish obtained locally weighing 100-120 g (5-7 in. long) were kept in aerated
water at 16° C for at least 1 week before use. Transfer to a hypertonic saline environment
took place in four stages. Sodium chloride was added to the water on alternate
days to give final concentrations of 100, 150, 175 and 190 mn-NaCl. The concen