I am interested in looking at indicators of osmoregulatory performance (plasma chloride, plasma sodium, haematocrit, cortisol etc.) in salmon smolts after a period of exposure to salt water. Ideally, fish would be euthanized (overdose of MS-222 or blunt cranial trauma) prior to blood sampling (either extracted from the caudal vein with a vacutainer syringe or by tail ablation). Does anyone have experience with extracting viable, unclotted blood samples from euthanized (rather than heavily anesthetized) fish? Is it possible and are there any special considerations that must be taken into account?