Introduction: This experiment was conducted to investigate the following hypothesis: Cold water temperature will decrease the respiration rate of a goldfish. Fish breathe by exchanging gasses through gills that are located in the gill cavity. The fish push water across the gills to gain O2 and to dispose of CO2 (Hamilton). Each time the fish breathes, the gill cover (or operculum) moves. This shows an accurate reading of the breathing rate. Goldfish are Ectotherms, meaning that they do not have
at each given temperature. Therefore, this constant and continuous re-oxygenation created an even, straight line at the beginning of our experiment as our system was open. This is because there was no difference in the concentration of oxygen over time. However, once the bubbler was moved and the system became closed, oxygen was not replenished as the goldfish carried out cellular respiration thus allowing us to measure the downward slope of the graph as less and less oxygen was present in the water