Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: August 5, 2003
Publication Date: March 4, 2004
Citation: Davis Jr, K.B., Small, B. 2004. Use of metomidate to determine the secretion and clearance rates of cortisol in sunshine bass and channel catfish [abstract]. Aquaculture America Conference. p. 151. Technical Abstract: Yearling sunshine bass and channel catfish were subjected to a standard confinement stress and a recovery period in the presence or absence of 1.5 mg/l metomidate hydrochloride. Plasma cortisol in sunshine bass increased from about 13 ng/ml to 120 ng/ml and plasma glucose increased from about 53 mg/dl to 93 mg/dl during the 15 minutes confinement in sunshine bass. When fish recovered in water without metomidate, cortisol continued to increase and reached the highest concentration 30 minutes after removal of the stress. Cortisol then fell regularly for the next 20 minutes. Plasma cortisol in bass allowed to recover in metomidate continued to increase for five minutes after the stress and then fell steadily for the next 40 minutes. Plasma glucose concentrations increased only slightly after removal of the stress and remained high during the hour of recovery. Fish recovering in metomidate had consistently higher glucose concentrations than controls, but were significantly higher only after 15 and 60 minutes during recovery. Plasma cortisol in channel catfish increased from about 9 to about 54 ng/ml and plasma glucose increased from about 26 to about 58 during a 50 minute confinement stress. Cortisol began to decrease immediately during the recovery period and fell more rapidly in fish held in metomidate than in controls. Glucose was highly variable but fell more slowly than cortisol and was typically, but not always significantly higher in metomidate treated fish than in controls. Plasma cortisol and glucose changes were higher and faster in sunshine bass than in channel catfish, however, the decrease in plasma cortisol began sooner during recovery and was faster in channel catfish.