Temperature Effects on Goldfish Respiration Rates

Introduction

All living organisms maintain homeostasis in their own ways to survive. One mechanism organisms use to maintain homeostasis is through respiration. Respiration is the process by which organisms exchange gases with their environment, or breathe. Organisms use either anaerobic or aerobic respiration. Aerobic respiration occurs when oxygen is taken into the body and transported to all of the cells (White and Campo 2013).

This experiment was designed to identify the effects of temperature changes on the respiration rate of goldfish. The null hypothesis is that as the temperature of the water decreases, there is a linear decrease in the respiration of the goldfish.

Materials and Methods

Two 600 mL glass beakers filled with 150 mL of aged water were used as containment vessels. Two goldfish were each placed into a separate 600 mL glass beaker. The beakers containing goldfish were designated as "Beaker 1" (control fish) and "Beaker 2" (experimental fish). Two additional 600 mL plastic beakers were obtained: one filled with two-thirds ice and water, and the other filled with aged water.

Water temperature in both Beaker 1 and Beaker 2 was measured using a thermometer and recorded. Each goldfish's breathing rate was determined by counting the number of times the goldfish's operculum (gill cover) contracted over a 60-second period, and results were recorded. Ice water was then added to Beaker 2 until the temperature decreased by 2°C. Aged water was added to Beaker 1 to maintain equal water levels in both beakers.

New temperatures were recorded and the number of breaths taken by both fish in 60 seconds were counted and recorded. This procedure was repeated six additional times, with the water temperature of Beaker 2 decreasing by 2°C each iteration. The water temperature in Beaker 2 ranged from 22°C at the start to 10°C at the end. As the temperature decreased, the number of breaths the goldfish took also decreased.

Results

The average respiration rate for the control goldfish in Beaker 1 was 95 breaths per 60 seconds, showing no change throughout the experiment. Data from all test groups indicated that water temperature significantly affected the respiration rate of the goldfish. The average respiration rate for the goldfish during cold water treatment in Beaker 2 ranged from 100 breaths at the beginning of the experiment to 25 breaths at the end of the experiment. The individual goldfish in Beaker 2 specifically ranged from 103 to 21 breaths per 60 seconds.

Discussion

Since the only variable that changed was the water temperature, this confirms that temperature was the true causal factor. Figure 1 illustrates the effect of temperature on breaths per 60 seconds, clearly showing a decrease in respiration rate as water temperature declined.

After the experiments were completed, the null hypothesis and alternative hypothesis were reviewed. Because water temperature did affect the respiration rate of the goldfish, the null hypothesis was rejected and the alternative hypothesis was accepted. While other environmental factors may have played a minor role in the respiration rate, the experiment provided strong evidence that the decrease in water temperature was a significant controlling factor.

The significance of this experiment is that scientists may be able to conclude that fish like goldfish are more active during warmer summer months and more inactive during colder months when water temperature is lower. This relationship between temperature and metabolic activity reflects broader principles of fish physiology.

While the results appear to support the hypothesis, several sources of error could have altered the findings. For example, the individual counting the breaths of the fish may not have accurately counted every breath, introducing measurement error. This experiment would have been more accurate if it had been repeated numerous times with multiple fish to establish statistical reliability. Additionally, the experiment could be modified to test the opposite relationship by increasing, rather than decreasing, the water temperature to see if respiration rate increases correspondingly.

Conclusion

This experiment investigated the effects of temperature on goldfish respiration rates and found a significant negative correlation between decreasing water temperature and breathing frequency.