Influence of sampling conditions on blood chemistry values of Adriatic sturgeon Acipenser naccarii (Bonaparte, 1836)

Data on the blood chemistry of a chondrostean fish, the Adriatic sturgeon ( Acipenser naccarii), are reported as measured with different sampling proce dures, and as related to rearing conditions and age. Serum cortisol, glucos e, osmolality, Na+, Cl-, Ca2+ and total protein concentrations were measure d. Reference values for the blood chemistry of farmed sturgeon were measure d on samples from resting undisturbed animals collected via a chronic indwe lling catheter in the dorsal aorta that was implanted under anaesthesia. Fo llowing 24h recovery from catheterization, serum cortisol, glucose and osmo lality levels were 9.4 ng/ml, 58.8 mg/dl and 261.4 mOsm/kg, respectively. F urthermore, blood samples collected with the chronic indwelling catheters i ndicated that the surgical procedure of cannulation caused a stress respons e, with physiological changes that followed a pattern like that described i n teleosts. Cortisol, glucose and osmolality were more sensitive to stress than the other variables measured. Sampling by cardiac puncture tended to b e associated with elevated serum cortisol levels in older, larger sturgeon, but not in young fish. Greater capture, confinement and handling stress in older, larger, sturgeon may have been responsible for this and other age-r elated differences in blood chemistry values measured following cardiac pun cture. Within the same age class, both rearing conditions and temperature a ffected cortisol, sodium and total protein concentrations significantly. An aesthesia did not appear to reduce the degree of stress associated with car diac puncture but altered serum ion concentrations.