Razorback suckers are selected from a stocking cohort for their size and are anesthetized in tricaine methanesulfonate (MS222). When fish lose equilibrium, they are weighed, measured, and placed in a damp cradle as shown. The gills are periodically flushed with clean water or MS222 solution to maintain anesthesia.

Surgery site (upper abdomen) is aseptically prepared with iodine and equipment is sanitized with alcohol.

An incision is placed in the upper abdomen to allow implantation of the sonic telemetry tag.

The sonic telemetry tag is inserted into the body cavity via the incision. The tag shown here is a 14-month tag with a motion-sensitive mortality switch and is approximately the size of a AA battery. Shorter lifespan tags are much smaller.

Once the tag is inserted, the wound is closed with three sutures.

A second pair of hands is often helpful to insure that the sutures are well-placed and are tight. Once the wound is closed, the fish is placed in freshwater and the anesthesia wears off within a few minutes. The entire surgical process takes <10 minutes per fish and has a low mortality rate.