Haematology of juvenile Acipenser oxyrinchus and Acipenser brevirostrum at rest and following forced activity

Abstract

In vivo experiments were conducted to examine the haematology of juveniles from two relic bony fishes, Atlantic sturgeon Acipenser oxyrhinchus and shortnose sturgeon Acipenser brevirostrum. Oxygen transport characteristics (haematocrit, haemoglobin and mean erythrocytic haemoglobin concentration), ionic composition (Na þ , Cl À , K þ and osmolality), metabolite concentration (lactate, cortisol and glucose) and protein content in blood were measured or calculated at rest and during recovery from forced activity. Under resting conditions, plasma osmolality and concentrations of Na þ , Cl À , lactate, cortisol and total protein were significantly different between Atlantic and shortnose sturgeon. All other resting variables were not different between species. Following forced activity, plasma lactate levels were significantly higher in both species than at rest. Plasma cortisol levels in both species were only significantly higher 1 h following forced activity compared to resting values. Plasma lactate levels were significantly higher in Atlantic sturgeon than in shortnose sturgeon, but these levels returned to resting levels by 1 h in both species. Cortisol increases were greater in shortnose sturgeon than in Atlantic sturgeon. In general, oxygen transport characteristics, blood glucose, plasma protein and plasma osmolality were not altered by forced activity in either sturgeon species. Overall, both species had reduced responses (i.e. the magnitude of changes in measured variables) to forced activity compared with teleosts. # 2005 The Fisheries Society of the British Isles

The hematological response to exhaustive exercise in ‘all-fish’ growth hormone transgenic common carp (Cyprinus carpio L.)

“…This is a standard technique used to stress fish in physiological studies (Wood, 1991;Milligan, 1996;Kieffer et al, 2001;Iwama, et al, 2004). Fish were considered to be physically exhausted when they lost equilibrium and were no longer responsive to manual chasing (Baker et al, 2005). The duration of exercise for each fish was not determined, but ranged between about 7 and 10 min.…”

Complete intracellular pH protection during extracellular pH depression is associated with hypercarbia tolerance in white sturgeon,Acipenser transmontanus

“…White sturgeon were placed into a recirculating system (Pw O 2 Ͼ 15.0 kPa, and Pw CO 2 Ͻ 0.03 kPa PCO2), consisting of darkened plastic boxes (30 liters, flow rate ϳ3 l/min, 17°C), for 24 h prior to experiments. This period is sufficient to allow recovery from handling stress in sturgeon (e.g., 2,3,15). Normocarbic white sturgeon were terminally sampled immediately following this habituation period (control or preexposure group).…”

“…During short-term exposure (days) to hypercarbia, most fish species studied to date are not capable of increasing plasma HCO 3 Ϫ (in exchange with Cl Ϫ ) Ͼ 27-33 mmol/l, and thus cannot fully compensate for the respiratory acidosis associated with CO 2 levels greater than ϳ2 kPa PCO 2 (15 Torr PCO 2 , where 1 Torr equals ϳ0.133 kPa) (6,25). This failure is associated with mortality, although surprisingly little research has described CO 2 -related toxicity (23,27).…”

Oxygen dynamics around buried lesser sandeelsAmmodytes tobianus(Linnaeus 1785): mode of ventilation and oxygen requirements

“…Being buried has the obvious advantage of being hidden but despite that, an anaerobic metabolic component could be a necessary consequence, or adaptation, of this behaviour. However, we find it unlikely that a 50% decrease in the O 2 requirements can be explained by anaerobic metabolism, as this would require massive accumulation of lactate, well above previous measurements for other fish (Milligan and Wood, 1987;Baker et al, 2005). (3) We cannot exclude elevated oxygen uptake of specimens confined in a small respirometer where they cannot bury.…”