Effects of anaesthetic MS 222 on the orientation of juvenile salmon, Oncorhynchus tschawytscha Walbaum

Abstract

Juvenile salmon, Oncorbynchus tschau~ytscha Walbaum, were trained to orientate in a direction (270") and then anaesthetized with ethyl m-aminobenzoate methane sulphonate (MS 222) in a test to determine whether anaesthesia affected the learnt orientation.Before anaesthesia thecontrol group of twelve fish showed a mean unimodal orientation of 264" and a bimodal axis of orientation of 258"/78" with a confidence limit (second order analysis) of 218' +-+285'. After administration of MS 222 nine out of ten fish showed marked changes in orientation and random behaviour, persisting in two fish for more than 14 days. The mean of means unimodal orientation, after anaesthesia, was 337" (random) and the bimodal axis of orientation was 337"j157" (random).Eight weeks after completion of the anaesthesia trial the fish were retested. Each fish, except one, showed a mean bimodal axis oforientation that fell within the confidence limit of the control. The mean axis of orientation for ten fish ovcr a 3-day period was 270'/90", (r)=0,28.The results support the view that the reference orientation in this study (270) was a learnt, not an innate directional preference. The effects anaesthesia may have on salmon behaviour during migration are discussed.

Use of electronarcosis to immobilize juvenile lake and shortnose sturgeons for handling and the effects on their behavior

“…Chemical anesthetics can be very expensive and may alter fish physiology and behavior for a few hours to 14 days after use (Goddard et al, 1974;Taylor, 1988). The induction of electronarcosis was found to be a good technique for immobilizing fish for measuring and other noninvasive procedures.…”

“…The equipment needed for immobilizing fish (DC power supply, holding tank, and screen electrodes) costs <$400 and can be transported into the field and powered with a battery. Chemical anesthetics can be very expensive and may alter fish physiology and behavior for a few hours to 14 days after use (Goddard et al, 1974;Taylor, 1988). The induction of electronarcosis is a good alternative technique for immobilizing fish and deserves more investigation and use.…”

Behavioural Effects of the Commonly Used Fish Anaesthetic Tricaine Methanesulfonate (MS-222) on Zebrafish (Danio rerio) and Its Relevance for the Acetic Acid Pain Test

“…It is possible that more cognitively demanding tasks may be influenced by anaesthesia to a larger degree than swimming and position in the tank. Juvenile salmonids that had been trained in an orienting task lost their learnt orientation towards the direction of food for several days after anaesthesia in tricaine [24] . Lastly, the acetic acid test is often carried out in the home-tank of the fish (e.g.…”

Co-ordinator

“…lowered pH), hypotonia (= reduced blood pressure), raised blood glucose, blood lactate and haematocrit . In addition to physiological deterioration of blood parameters, hypoxia can cause brain damage, which interferes with directional orientation (Taylor, 1988), or alters temperature preferences (Goddard et al, 1974).…”