Hobbies And Interests
Food Brand and Fish Growth
Many different brands of fish food are available for feeding goldfish. A student may explore whether using a different type of food will result in better growth than using another brand. For this project, the student will need to set up several different 5-gallon fish tanks with about ten goldfish in each tank. The water temperature and amount of food should be equal. The fish should be weighed at the beginning of the project. To weigh fish, the student should first weigh a container full of water, then add the fish and subtract the first from the second weight. Each tank is labeled with the food used. The fish should be weighed every four days for at least a month to compare the weight gains for each type of food.
Goldfish Memory
Some people have questioned whether or not goldfish have long-term memories. A student can study the memory span of a goldfish by using training methods on the fish. Each day for a week, the student should place three different-colored plastic rings into the fish tank with food hanging in the same ring each time. The student should record the time that it takes for the fish to move toward the ring containing the food each day. After the first week, the student can introduce all three rings back into the tank without the food and note which ring, if any, the fish move toward.
Respiration Rate
Just like humans, goldfish have a rate of respiration that may change based on circumstances. This project requires the student to set up a 20-gallon fish tank that is divided into three sections with plastic dividers. The fish are housed in one section, one is an observation section and the third is where the fish go after observation. Once the fish are settled, the student should transfer the fish one at a time into the observation section and observe and record the rate of respiration. Each fish is moved to the "done" section after observation. The water temperature is then increased slightly, no more than 10 degrees Celsius, and the observations are made again. The student should repeat this process for several temperatures and record the results.
Depleted Oxygen
Even though goldfish live in water, they still require oxygen; they simply extract their oxygen from the water instead of the air. The student will need about three fish and two tanks to complete this project. The water in the first tank should be boiled first and then cooled to room temperature. Boiling the water removes some of the dissolved oxygen from the water. The other tank contains regular tap water at room temperature. Each fish should first be placed in the low-oxygen tank and observations should be recorded on the fish's respiration rate. The fish is then moved to the regular tank and the respiration rate is recorded. This experiment should be repeated for all three fish to average the results and make observations.