Table 2 Experimental water condition for river puffer, Takifugu obscurus and tiger puffer, T. rubripes in this anaesthetic experiment^*

Test parameters	Condition
pH	7.6±0.02
DO (dissolved oxygen; mg/L; Saturated concentration in 26°C)	7.5±0.32
Ammonia (ppm)	0.00
Nitric acid (ppm)	1.8±0.14
Nitrous acid (ppm)	0.01
Conductivity (µs/cm)	238

Test parameters were analyzed at 1 hr before experiment. The values are means of triplicate groups. Dissolved oxygen, pH and salinity were measured using an oxygen measurement electrode and a multi-data logger system (Oxyguard, Denmark). Ammonia, nitric acid, nitrous acid and conductivity were measured using spectrophotometer (DR2800, Colorado, USA).