If the specimen is to stand upon a pedestal of polished wood, with supporting rods from the belly, make the incision along center of belly full length. To prevent decay, stir three or four drops of forty per cent solution of formalin into a quart of water.
Squeeze a cloth from this, leaving it pretty moist, and wrap the fish in it, giving the wet cloth close contact with the skin. Do not apply formalin inside any skin to be used for mounting. Never eat the flesh of a fish thus kept.
Before skinning the fish, make careful outlines over him, both side and top views. When skin is removed make outlines of skinned carcass.
Handle a fish very carefully when skinning and cleaning, moving the specimen about or bending as little as possible during the entire operation. Lay the head to your left. Open the skin with scissors and make one long clean cut.
Lift edges of the skin and peel from flesh with a sharp knife or scalpel. Cut off base of fins, when encountered, with scissors or bone snips. Trim out most of skull with knife and bone snips, removing eyes from inside. Be sure to scrape all flesh from cheek inside of gill cover.
Remove flesh and fat from inside of skin with scraper, working from tail toward head. Scrape out with point of small knife blade the flesh that runs out thin over tail-fin bones.
This completes the skinning operation. The cleaned skin may be poisoned to advantage with either dry or solution arsenic, brushed in well.
If the specimen is opened on the side for panel mounting and we wish to follow a very simple method in mounting, one that is quite as practical as it is simple, we must take a different step than outline sketches before skinning. This is to make a complete body and head cast of the best side in plaster of paris. This does not include the fins. To make the cast neatly, lay the fish, best side up, in a slight hollow in a box of clean, damp sand. Pack the sand up under the fish body smoothly so that more than half of him rises in cameo style from the smooth surface.
Make up enough plaster to do the cast at once. To mix plaster properly, sprinkle it into the dish of water until a little will begin to stand out dry above the surface. Then with a spoon sunk deep in it, gently stir to evenness. It is then ready to pour. Before doing this, jar the pan upon the table a time or two to cause any possible bubbles to rise.
Pour evenly over the fish, or better still, dip it on with the spoon. The plaster should be thick enough to barely flow for making a proper cast.