The Effect of Temperature on The Aerobic Respiration of Tenebrio molitor (Coleoptera: Tenebrionidae) Measured Using A Simple Microrespirometer

 

Tested Studies in Laboratory Teaching, 2016, Volume 37

Kevin Miller

Abstract

Microrespirometers make a handy instrument for indirectly measuring respiration of small organisms such as plants or insects. This experiment involves the use of microrespirometers to indirectly measure the oxygen consumption of mealworms Tenebrio molitor (Order Coleoptera, Family Tenebrionidae). The respirometer adapted from Lee (1995) is made from a 1-ml syringe that has a capillary tube glued in the place of the needle. Additionally, there are two wads of cotton inside the syringe near the capillary tube one of which is standard absorbent cotton containing approximately 10 μl of a 15% KOH (potassium hydroxide) solution. The other is a portion of non-absorbent cotton that protects the test organism from the corrosive KOH. The capillary tube is sealed with a small amount of liquid that is added to the tube. Respirometers work by enclosing organisms or a sample of an organism in a chamber. The KOH, a highly corrosive basic liquid, can take CO2 (gas) out of the air and convert it to a solid. During cellular respiration CO2 (gas) is released as O2 is consumed. Since liquids and solids take up far less space than gases, the net result of the O2 loss and CO2 conversion from gas to solid is that the pressure decreases in the chamber. This pressure decrease is observed by the movement of liquid in the capillary tube. This liquid, referred to as manometer fluid, moves away from the capillary's opening and is measured using a millimeter ruler attached to the capillary tube.

Keywords:  respiratory physiology, respiration rate, respiration, aerobic respiration

Boston University (2015)