In a medium size or larger fish, use a pair of bone cutters to cut through the pectoral girdle above and below the pectoral fin. Using a heavy pair of disecting scissors, cut down along the ventral midline, through the pelvic girdle, almost to the vent. Cut the anterior peritoneal lining under the pectoral girdle. Make another incision starting above the pectoral fin to remove the lateral body wall and reveal the internal viscera. Take care not to cut the swim bladder or other internal organs.

A standard set of necropsy tools includes (counter- clockwise from bottom left) bone cutters, fine dissecting scissors, superfine dissecting scissors (optional), medium-fine rat-toothed forceps, a microbiological wire, and a pair of heavy dissecting scissors. These tools are expensive and easily made dull by improper use. Use the bone cutters for going through bone, and the heavy dissecting scissors to cut through skin, muscle and connective tissue. Use the fine scissors for delicate soft tissues only.