Experiment A. Fourteen fish were sampled
both by CT and CVP. In seven fish, 2 ml blood
were withdrawn by CVP and transferred to a
first plastic vial; then the caudal peduncle was
severed and 2 ml blood were allowed to drip
into another plastic vial. In the seven other
fish, 2 ml blood were sampled by CT first, then
bleeding from the caudal vessels was interrupted
by compression and 2 ml blood were sampled by
CVP. The needle penetrated caudal vessels approximately
2 cm cranially to the severance
plane. Blood was mixed with heparin, 20 IU/ml
(40 pi/sample). The total sampling time for each
fish was approximately 2 min.