Stomach Pump
Used properly, the stomach pump doesn't injure fish and can unlock secrets as to what fish are feeding on. Gently insert into the fish's throat and allow the suction of the pump bulb to suck out recently eaten food items. Then put a little water into the bulb and squeeze it out into a glass specimen vial. The glass vial allows you to see the insect's true color and shape much better than holding them in your hand.
