0.50 mm (0.020”) = Trout, salmon, tullibee
0.76 mm (0.030”) = Young fish – many species
1.00 mm (0.040”) = Bass, walleye, perch, sucker, sunfish
1.50 mm (0.060”) = Carp

Tips for taking scale samples:
Age determination of fish is easy if you are consistent. Take scale samples from a specific part of each fish. (a) On spiny-rayed fish, just below the lateral line and below the middle of the spiny dorsal fin. (b) For most soft-rayed fishes, the area between the lateral line and dorsal fin. (c) For trout, the area directly below the lateral line beneath the posterior end of the dorsal fin is best.

1. Place under a binocular dissection microscope in such a way that the groove is directly under the object lens.
2. Place a 5 to 10 mL sample in the trough.
3. The sample channel has a small plastic divider placed across the groove at one point to mark the start and finish of the count.
4. The plankton are counted as the wheel is rotated.
5. To maintain, wash with mild soap and soft water. Rinse completely with distilled water before drying. To remove surface scratches, buff gently with mild abrasive and soft flannel buffer, then wash as directed.

1. Check length and depth of your cell before use.
2. Fill cell with your sample using Hensen-Stempel pipettes.
3. Before counting, let it stand for at least 15 minutes to settle plankton. Count plankton on bottom of cell.
4. Calculate as per Standard Methods.

1. Run line through messenger so tapered end points toward lower line end.
2. Run line through hole in trip release and knot securely under the handle.
3. Attach line to bottle, calibrate if desired.
4. Set stoppers in position. Pull them out of bottle end and attach cable loop to pin. When cables are attached, lower slowly, counting marks.
5. Hold messenger to keep it from falling down the line before you are ready.
6. When the bottle is at desired depth, drop the messenger, tapered nose first, to strike the trip release pad.