Effect of short term exposure to the anaesthetic 2-phenoxyethanol on plasma osmolality of juvenile dusky kob, Argyrosomus japonicus (Sciaenidae)

The plasma osmolality of early juvenile dusky kob, Argyrosomus japonicus , exposed to 2-phenoxyethanol and control fish that were pithed prior to sampling, was investigated. Exposure to 2-phenoxyethanol, after 2, 4, 6, 8 and 10 min, did not alter plasma osmolality (Friedman test; P = 0.976). There was no significant relationship between the size of fish within the range 133–170 mm SL (40–85 g) and plasma osmolality. Finally, there was no significant difference in plasma osmolality between anaesthetized fish and the control group that were pithed directly after removal from the tanks. Anaesthetizing juvenile dusky kob with 2-phenoxyethanol prior to blood sampling did not affect plasma osmolality.