PRIMARY AND SECONDARY STRESS RESPONSES IN GOLDEN PERCH, MACQUARIA-AMBIGUA

Golden perch (Macquaria ambigua), a species of Australian freshwater f ish, were subjected to a number of simple stress procedures. Bloodsamp les were taken and levels of commonly measured primary and secondary s tress response parameters (cortisol, glucose and lactate) were determi ned. Anaesthesia and exertion of fish prior to bloodsampling affected resting levels of some of the parameters measured. Wild and aquarium-a cclimated golden perch had low plasma cortisol levels (<2 ng/ml). Most fish appeared to adapt well to aquarium conditions, although occasion al fish showed indications of being chronically stressed. Golden perch responded quickly to stress (<5 min), with increased plasma levels of cortisol and lactate. In contrast, glucose levels did not increase un til at least 10 min after the stress was initiated; by 30 min, however , the typical hyperglycaemic response was observed. Golden perch recov er rapidly from acute stress (<2.5 hr). Golden perch seem to acclimate quickly to conditions of chronic stress.