FIGURE 1 EXTERNAL STRUCTURES OF A PERCH 6. Referring to Figure 2, use scissors to cut on one side from the corner of the mouth to the front lower edge of the gill cover. Then remove the operculum. CAUTION: Use scissors and other sharp instruments with extreme care. Use scissors to remove a gill, and identify the fingerlike gill filaments. On the inside of the gill are sturdy projections called gill rakers. They help keep food away from the gills. Note that the gills open directly into the throat. Refer to Figure 3 for cutting open the trunk of the fish in steps 8–11. With a scalpel/scissor make an incision through the body wall of the fish. Cut along the belly of the fish from the front edge of the operculum through the trunk to the anus (cut a). CAUTION: Use scissors and other sharp instruments with extreme care. Cut up along the side of the fish to the backbone (cut b). Lift open the side of the fish, and cut forward through the ribs along the backbone to the tip of the operculum (cut c). Remove the portion of the trunk that you have cut away. 12. Use Figure 4 and your probe to locate and observe the following internal organs: air bladder, stomach, intestine, liver, kidneys, gonads (ovaries or testes), heart (atrium and ventricle), muscles, ribs, and vertebrae (backbone).
FIGURE 1 EXTERNAL STRUCTURES OF A PERCH 6. Referring to Figure 2, use scissors to cut on one side from the corner of the mouth to the front lower edge of the gill cover. Then remove the operculum. CAUTION: Use scissors and other sharp instruments with extreme care. Use scissors to remove a gill, and identify the fingerlike gill filaments. On the inside of the gill are sturdy projections called gill rakers. They help keep food away from the gills. Note that the gills open directly into the throat. Refer to Figure 3 for cutting open the trunk of the fish in steps 8–11. With a scalpel/scissor make an incision through the body wall of the fish. Cut along the belly of the fish from the front edge of the operculum through the trunk to the anus (cut a). CAUTION: Use scissors and other sharp instruments with extreme care. Cut up along the side of the fish to the backbone (cut b). Lift open the side of the fish, and cut forward through the ribs along the backbone to the tip of the operculum (cut c). Remove the portion of the trunk that you have cut away. 12. Use Figure 4 and your probe to locate and observe the following internal organs: air bladder, stomach, intestine, liver, kidneys, gonads (ovaries or testes), heart (atrium and ventricle), muscles, ribs, and vertebrae (backbone).
fish-dissection-lab.docx