EFFECTS OF DORSAL AORTA CANNULATION ON THE STRESS-RESPONSE OF CHANNELCATFISH (ICTALURUS-PUNCTATUS)

The stress response to dorsal aorta cannulation and serial blood sampl ing was examined in the channel catfish Ictalurus punctatus. Channel c atfish cannulated and repetitively sampled once a day for 7 days did n ot exhibit a change in response to surgery or to the 24h sample regime as measured by plasma cortisol, glucose, and chloride. In fish that w ere either serially bled (0, 1, 3, 6, 9, 12, 24, and 48h) immediately after surgery or allowed to recover 6 days before being serially bled, overall plasma cortisol levels were higher than those of fish bled ev ery 24h. Catfish serially bled immediately after surgery had significa ntly higher plasma glucose levels compared with catfish allowed to rec over from surgery 6 days before serial sampling. Although channel catf ish recover from cannulation surgery in 24h, a longer recovery period may be needed prior to serial sampling if the samples are taken more f requently than every 24h.