This commercially prepared display shows a dissection of the anterior half of a typical ray-finned fish. Note the arrangement of the fins, which are supported by bony rays. Non-paired fins include the first dorsal fin (1) and the second dorsal fin and ventral anal fin seen on the next page.  Of the two sets of paired fins, only the pelvic fin (2) is shown; the pectoral fins and operculum (a bony flap that covers and protect the gills) have been removed to facilitate the dissection.  Internal structures that can be seen on the dissection mount include the gills (3), heart (4), brain (5), dorsal nerve cord (6), liver (7), stomach (8), gonad (9) and intestine (10).  The position of the swim bladder (which has been deflated) is shown by arrow number 11.