Effects of different surgical techniques: suture material and location of incision site on the behaviour of rainbow trout (Oncorhynchus mykiss)

We examined the effects of midline and off midline incision locations, acid incisions closed with monofilament or silk suture on spontaneous swimming behaviour in fish. Each fish had a dummy transmitter surgically implanted into its peritoneal cavity. The behaviour of fish in each treatment was estimated using three different measures: the number of C-turns performed, the number of sprints performed, and the total distance travelled. There were no significant differences (p > 0.05) among treatments with respect to the number of C-turns or sprints made. Fish closed with monofilament with an off midline incision travelled significantly less distance (p = 0.014) than fish closed with monofilament and a midline incision, but neither treatment was significantly different from control fish. The three measures of behaviour: C-turns, sprints and distance travelled, were not affected either by the amount of inflammation at the incision site or by the amount of inflammation at the entry and exit points of the sutures, regardless of the treatment. The surgical techniques tested had little effect on fish behaviour post surgery, regardless of inflammation levels. It seems that behaviour of fish may not be affected by surgery, but further testing examining more subtle behaviours will have to be performed.